1page.title=<uses-sdk> 2page.tags="api levels","sdk version","minsdkversion","targetsdkversion","maxsdkversion" 3@jd:body 4 5 6<div id="qv-wrapper"> 7<div id="qv"> 8 9<h2>In this document</h2> 10<ol> 11 <li><a href="#ApiLevels">What is API Level?</a></li> 12 <li><a href="#uses">Uses of API Level in Android</a></li> 13 <li><a href="#considerations">Development Considerations</a> 14 <ol> 15 <li><a href="#fc">Application forward compatibility</a></li> 16 <li><a href="#bc">Application backward compatibility</a></li> 17 <li><a href="#platform">Selecting a platform version and API Level</a></li> 18 <li><a href="#apilevel">Declaring a minimum API Level</a></li> 19 <li><a href="#testing">Testing against higher API Levels</a></li> 20 </ol> 21 </li> 22 <li><a href="#provisional">Using a Provisional API Level</a></li> 23 <li><a href="#filtering">Filtering the Reference Documentation by API Level</a></li> 24</ol> 25</div> 26</div> 27 28<div class="sidebox-wrapper"> 29<div class="sidebox"> 30 <img src="{@docRoot}assets/images/icon_play.png" style="float:left;margin:0;padding:0;"> 31 <p style="color:#669999;padding-top:1em;">Google Play Filtering</p> 32 <p style="padding-top:1em;">Google Play uses the <code><uses-sdk></code> 33 attributes declared in your app manifest to filter your app from devices 34 that do not meet it's platform version requirements. Before setting these 35 attributes, make sure that you understand 36 <a href="{@docRoot}google/play/filters.html">Google Play filters</a>. </p> 37 </div> 38</div> 39 40<dl class="xml"> 41<dt>syntax:</dt> 42<dd><pre> 43<uses-sdk android:<a href="#min">minSdkVersion</a>="<i>integer</i>" 44 android:<a href="#target">targetSdkVersion</a>="<i>integer</i>" 45 android:<a href="#max">maxSdkVersion</a>="<i>integer</i>" /></pre></dd> 46 47<dt>contained in:</dt> 48<dd><code><a href="{@docRoot}guide/topics/manifest/manifest-element.html"><manifest></a></code></dd> 49 50<dt>description:</dt> 51<dd>Lets you express an application's compatibility with one or more versions of the Android platform, 52by means of an API Level integer. The API Level expressed by an application will be compared to the 53API Level of a given Android system, which may vary among different Android devices. 54</p> 55 56<p>Despite its name, this element is used to specify the API Level, <em>not</em> 57the version number of the SDK (software development kit) or Android platform. 58The API Level is always a single integer. You cannot derive the API Level from 59its associated Android version number (for example, it is not the same as the 60major version or the sum of the major and minor versions).</p> 61 62<p>Also read the document about 63<a href="{@docRoot}tools/publishing/versioning.html">Versioning Your Applications</a>. 64</p></dd> 65 66<dt>attributes:</dt> 67 68<dd> 69<dl class="attr"> 70 <dt><a name="min"></a>{@code android:minSdkVersion}</dt> 71 <dd>An integer designating the minimum API Level required 72 for the application to run. The Android system will prevent the user from installing 73 the application if the system's API Level is lower than the value specified in 74 this attribute. You should always declare this attribute. 75 76 <p class="caution"><strong>Caution:</strong> If you do not declare this 77 attribute, the system assumes a default value of "1", which indicates that your 78 application is compatible with all versions of Android. If your application is 79 <em>not</em> compatible with all versions (for instance, it uses APIs introduced 80 in API Level 3) and you have not declared the proper <code>minSdkVersion</code>, 81 then when installed on a system with an API Level less than 3, the application 82 will crash during runtime when attempting to access the unavailable APIs. For 83 this reason, be certain to declare the appropriate API Level in the 84 <code>minSdkVersion</code> attribute.</p> 85 </dd> 86 87 <dt><a name="target"></a>{@code android:targetSdkVersion}</dt> 88 <dd>An integer designating the API Level that the application targets. If not set, the default 89value equals that given to {@code minSdkVersion}. 90 91 <p>This attribute informs the system that you have tested against the target version and the 92system should not enable any compatibility behaviors to maintain your app's forward-compatibility 93with the target version. The application is still able to run on older versions (down to {@code 94minSdkVersion}).</p> 95 96 <p>As Android evolves with each new version, some behaviors and even appearances might change. 97However, if the API level of the platform is higher than the version declared by your app's {@code 98targetSdkVersion}, the system may enable compatibility behaviors to ensure that your app 99continues to work the way you expect. You can disable such compatibility 100behaviors by specifying {@code targetSdkVersion} to match the API 101level of the platform on which it's running. For example, setting this value to "11" or higher 102allows the system to apply a new default theme (Holo) to your app when running on Android 3.0 or 103higher and also disables <a href="{@docRoot}guide/practices/screen-compat-mode.html">screen 104compatibility mode</a> when running on larger screens (because support for API level 11 implicitly 105supports larger screens).</p> 106 107 <p>There are many compatibility behaviors that the system may enable based on the value you set 108for this attribute. Several of these behaviors are described by the corresponding platform versions 109in the {@link android.os.Build.VERSION_CODES} reference.</p> 110 111 <p>To maintain your application along with each Android release, you should increase 112the value of this attribute to match the latest API level, then thoroughly test your application on 113the corresponding platform version.</p> 114 115 <p>Introduced in: API Level 4</p> 116 </dd> 117 118 <dt><a name="max"></a>{@code android:maxSdkVersion}</dt> 119 <dd>An integer designating the maximum API Level on which the application is 120 designed to run. 121 122 <p>In Android 1.5, 1.6, 2.0, and 2.0.1, the system checks the value of this 123 attribute when installing an application and when re-validating the application 124 after a system update. In either case, if the application's 125 <code>maxSdkVersion</code> attribute is lower than the API Level used by 126 the system itself, then the system will not allow the application to be 127 installed. In the case of re-validation after system update, this effectively 128 removes your application from the device. 129 130 <p>To illustrate how this attribute can affect your application after system 131 updates, consider the following example: </p> 132 133 <p>An application declaring <code>maxSdkVersion="5"</code> in its 134 manifest is published on Google Play. A user whose device is running Android 135 1.6 (API Level 4) downloads and installs the app. After a few weeks, the user 136 receives an over-the-air system update to Android 2.0 (API Level 5). After the 137 update is installed, the system checks the application's 138 <code>maxSdkVersion</code> and successfully re-validates it. The 139 application functions as normal. However, some time later, the device receives 140 another system update, this time to Android 2.0.1 (API Level 6). After the 141 update, the system can no longer re-validate the application because the system's 142 own API Level (6) is now higher than the maximum supported by the application 143 (5). The system prevents the application from being visible to the user, in 144 effect removing it from the device.</p> 145 146 <p class="warning"><strong>Warning:</strong> Declaring this attribute is not 147 recommended. First, there is no need to set the attribute as means of blocking 148 deployment of your application onto new versions of the Android platform as they 149 are released. By design, new versions of the platform are fully 150 backward-compatible. Your application should work properly on new versions, 151 provided it uses only standard APIs and follows development best practices. 152 Second, note that in some cases, declaring the attribute can <strong>result in 153 your application being removed from users' devices after a system 154 update</strong> to a higher API Level. Most devices on which your application 155 is likely to be installed will receive periodic system updates over the air, so 156 you should consider their effect on your application before setting this 157 attribute.</p> 158 159 <p style="margin-bottom:1em;">Introduced in: API Level 4</p> 160 161 <div class="special">Future versions of Android (beyond Android 2.0.1) will no 162longer check or enforce the <code>maxSdkVersion</code> attribute during 163installation or re-validation. Google Play will continue to use the attribute 164as a filter, however, when presenting users with applications available for 165download. </div> 166 </dd> 167 168 169</dl></dd> 170 171<!-- ##api level indication## --> 172<dt>introduced in:</dt> 173<dd>API Level 1</dd> 174 175</dl> 176 177 178 179 180 181<!--- CONTENT FROM OLD API LEVEL DOC ----> 182 183 184 185 186<h2 id="ApiLevels">What is API Level?</h2> 187 188<p>API Level is an integer value that uniquely identifies the framework API 189revision offered by a version of the Android platform.</p> 190 191<p>The Android platform provides a framework API that applications can use to 192interact with the underlying Android system. The framework API consists of:</p> 193 194<ul> 195<li>A core set of packages and classes</li> 196<li>A set of XML elements and attributes for declaring a manifest file</li> 197<li>A set of XML elements and attributes for declaring and accessing resources</li> 198<li>A set of Intents</li> 199<li>A set of permissions that applications can request, as well as permission 200enforcements included in the system</li> 201</ul> 202 203<p>Each successive version of the Android platform can include updates to the 204Android application framework API that it delivers. </p> 205 206<p>Updates to the framework API are designed so that the new API remains 207compatible with earlier versions of the API. That is, most changes in the API 208are additive and introduce new or replacement functionality. As parts of the API 209are upgraded, the older replaced parts are deprecated but are not removed, so 210that existing applications can still use them. In a very small number of cases, 211parts of the API may be modified or removed, although typically such changes are 212only needed to ensure API robustness and application or system security. All 213other API parts from earlier revisions are carried forward without 214modification.</p> 215 216<p>The framework API that an Android platform delivers is specified using an 217integer identifier called "API Level". Each Android platform version supports 218exactly one API Level, although support is implicit for all earlier API Levels 219(down to API Level 1). The initial release of the Android platform provided 220API Level 1 and subsequent releases have incremented the API Level.</p> 221 222<p>The table below specifies the API Level supported by each version of the 223Android platform. For information about the relative numbers of devices that 224are running each version, see the <a href="{@docRoot}about/dashboards/index.html">Platform 225Versions dashboards page</a>.</p> 226 227<table> 228 <tr><th>Platform Version</th><th>API Level</th><th>VERSION_CODE</th><th>Notes</th></tr> 229 230 <tr><td><a href="{@docRoot}about/versions/android-4.2.html">Android 4.2, 4.2.2</a></td> 231 <td><a href="{@docRoot}sdk/api_diff/17/changes.html" title="Diff Report">17</a></td> 232 <td>{@link android.os.Build.VERSION_CODES#JELLY_BEAN_MR1}</td> 233 <td><a href="{@docRoot}about/versions/jelly-bean.html">Platform 234Highlights</a></td></tr> 235 236 <tr><td><a href="{@docRoot}about/versions/android-4.1.html">Android 4.1, 4.1.1</a></td> 237 <td><a href="{@docRoot}sdk/api_diff/16/changes.html" title="Diff Report">16</a></td> 238 <td>{@link android.os.Build.VERSION_CODES#JELLY_BEAN}</td> 239 <td><a href="{@docRoot}about/versions/jelly-bean.html">Platform 240Highlights</a></td></tr> 241 242 <tr><td><a href="{@docRoot}about/versions/android-4.0.3.html">Android 4.0.3, 4.0.4</a></td> 243 <td><a href="{@docRoot}sdk/api_diff/15/changes.html" title="Diff Report">15</a></td> 244 <td>{@link android.os.Build.VERSION_CODES#ICE_CREAM_SANDWICH_MR1}</td> 245 <td rowspan="2"><a href="{@docRoot}about/versions/android-4.0-highlights.html">Platform 246Highlights</a></td></tr> 247 248 <tr><td><a href="{@docRoot}about/versions/android-4.0.html">Android 4.0, 4.0.1, 4.0.2</a></td> 249 <td><a href="{@docRoot}sdk/api_diff/14/changes.html" title="Diff Report">14</a></td> 250 <td>{@link android.os.Build.VERSION_CODES#ICE_CREAM_SANDWICH}</td> 251 </tr> 252 253 <tr><td><a href="{@docRoot}about/versions/android-3.2.html">Android 3.2</a></td> 254 <td><a href="{@docRoot}sdk/api_diff/13/changes.html" title="Diff Report">13</a></td> 255 <td>{@link android.os.Build.VERSION_CODES#HONEYCOMB_MR2}</td> 256 <td><!-- <a href="{@docRoot}about/versions/android-3.2-highlights.html">Platform 257Highlights</a>--></td></tr> 258 259 <tr><td><a href="{@docRoot}about/versions/android-3.1.html">Android 3.1.x</a></td> 260 <td><a href="{@docRoot}sdk/api_diff/12/changes.html" title="Diff Report">12</a></td> 261 <td>{@link android.os.Build.VERSION_CODES#HONEYCOMB_MR1}</td> 262 <td><a href="{@docRoot}about/versions/android-3.1-highlights.html">Platform Highlights</a></td></tr> 263 264 <tr><td><a href="{@docRoot}about/versions/android-3.0.html">Android 3.0.x</td> 265 <td><a href="{@docRoot}sdk/api_diff/11/changes.html" title="Diff Report">11</a></td> 266 <td>{@link android.os.Build.VERSION_CODES#HONEYCOMB}</td> 267 <td><a href="{@docRoot}about/versions/android-3.0-highlights.html">Platform Highlights</a></td></tr> 268 269 <tr><td><a href="{@docRoot}about/versions/android-2.3.3.html">Android 2.3.4<br>Android 2.3.3</td> 270 <td><a href="{@docRoot}sdk/api_diff/10/changes.html" title="Diff Report">10</a></td> 271 <td>{@link android.os.Build.VERSION_CODES#GINGERBREAD_MR1}</td> 272 <td rowspan="2"><a href="{@docRoot}about/versions/android-2.3-highlights.html">Platform 273Highlights</a></td></tr> 274 275 <tr><td><a href="{@docRoot}about/versions/android-2.3.html">Android 2.3.2<br>Android 2.3.1<br>Android 2762.3</td> 277 <td><a href="{@docRoot}sdk/api_diff/9/changes.html" title="Diff Report">9</a></td> 278 <td>{@link android.os.Build.VERSION_CODES#GINGERBREAD}</td> 279 </tr> 280 281 <tr><td><a href="{@docRoot}about/versions/android-2.2.html">Android 2.2.x</td> 282 <td ><a href="{@docRoot}sdk/api_diff/8/changes.html" title="Diff Report">8</a></td> 283 <td>{@link android.os.Build.VERSION_CODES#FROYO}</td> 284 <td><a href="{@docRoot}about/versions/android-2.2-highlights.html">Platform Highlights</a></td></tr> 285 286 <tr><td><a href="{@docRoot}about/versions/android-2.1.html">Android 2.1.x</td> 287 <td><a href="{@docRoot}sdk/api_diff/7/changes.html" title="Diff Report">7</a></td> 288 <td>{@link android.os.Build.VERSION_CODES#ECLAIR_MR1}</td> 289 <td rowspan="3" ><a href="{@docRoot}about/versions/android-2.0-highlights.html">Platform 290Highlights</a></td></tr> 291 292 <tr><td><a href="{@docRoot}about/versions/android-2.0.1.html">Android 2.0.1</td> 293 <td><a href="{@docRoot}sdk/api_diff/6/changes.html" title="Diff Report">6</a></td> 294 <td>{@link android.os.Build.VERSION_CODES#ECLAIR_0_1}</td> 295 </tr> 296 297 <tr><td><a href="{@docRoot}about/versions/android-2.0.html">Android 2.0</td> 298 <td><a href="{@docRoot}sdk/api_diff/5/changes.html" title="Diff Report">5</a></td> 299 <td>{@link android.os.Build.VERSION_CODES#ECLAIR}</td> 300 </tr> 301 302 <tr><td><a href="{@docRoot}about/versions/android-1.6.html">Android 1.6</td> 303 <td><a href="{@docRoot}sdk/api_diff/4/changes.html" title="Diff Report">4</a></td> 304 <td>{@link android.os.Build.VERSION_CODES#DONUT}</td> 305 <td><a href="{@docRoot}about/versions/android-1.6-highlights.html">Platform Highlights</a></td></tr> 306 307 <tr><td><a href="{@docRoot}about/versions/android-1.5.html">Android 1.5</td> 308 <td><a href="{@docRoot}sdk/api_diff/3/changes.html" title="Diff Report">3</a></td> 309 <td>{@link android.os.Build.VERSION_CODES#CUPCAKE}</td> 310 <td><a href="{@docRoot}about/versions/android-1.5-highlights.html">Platform Highlights</a></td></tr> 311 312 <tr><td><a href="{@docRoot}about/versions/android-1.1.html">Android 1.1</td> 313 <td>2</td> 314 <td>{@link android.os.Build.VERSION_CODES#BASE_1_1}</td><td></td></tr> 315 316 <tr><td>Android 1.0</td> 317 <td>1</td> 318 <td>{@link android.os.Build.VERSION_CODES#BASE}</td> 319 <td></td></tr> 320</table> 321 322 323<h2 id="uses">Uses of API Level in Android</h2> 324 325<p>The API Level identifier serves a key role in ensuring the best possible 326experience for users and application developers: 327 328<ul> 329<li>It lets the Android platform describe the maximum framework API revision 330that it supports</li> 331<li>It lets applications describe the framework API revision that they 332require</li> 333<li>It lets the system negotiate the installation of applications on the user's 334device, such that version-incompatible applications are not installed.</li> 335</ul> 336 337<p>Each Android platform version stores its API Level identifier internally, in 338the Android system itself. </p> 339 340<p>Applications can use a manifest element provided by the framework API — 341<code><uses-sdk></code> — to describe the minimum and maximum API 342Levels under which they are able to run, as well as the preferred API Level that 343they are designed to support. The element offers three key attributes:</p> 344 345<ul> 346<li><code>android:minSdkVersion</code> — Specifies the minimum API Level 347on which the application is able to run. The default value is "1".</li> 348<li><code>android:targetSdkVersion</code> — Specifies the API Level 349on which the application is designed to run. In some cases, this allows the 350application to use manifest elements or behaviors defined in the target 351API Level, rather than being restricted to using only those defined 352for the minimum API Level.</li> 353<li><code>android:maxSdkVersion</code> — Specifies the maximum API Level 354on which the application is able to run. <strong>Important:</strong> Please read the <a 355href="{@docRoot}guide/topics/manifest/uses-sdk-element.html"><code><uses-sdk></code></a> 356documentation before using this attribute. </li> 357</ul> 358 359<p>For example, to specify the minimum system API Level that an application 360requires in order to run, the application would include in its manifest a 361<code><uses-sdk></code> element with a <code>android:minSdkVersion</code> 362attribute. The value of <code>android:minSdkVersion</code> would be the integer 363corresponding to the API Level of the earliest version of the Android platform 364under which the application can run. </p> 365 366<p>When the user attempts to install an application, or when revalidating an 367appplication after a system update, the Android system first checks the 368<code><uses-sdk></code> attributes in the application's manifest and 369compares the values against its own internal API Level. The system allows the 370installation to begin only if these conditions are met:</p> 371 372<ul> 373<li>If a <code>android:minSdkVersion</code> attribute is declared, its value 374must be less than or equal to the system's API Level integer. If not declared, 375the system assumes that the application requires API Level 1. </li> 376<li>If a <code>android:maxSdkVersion</code> attribute is declared, its value 377must be equal to or greater than the system's API Level integer. 378If not declared, the system assumes that the application 379has no maximum API Level. Please read the <a 380href="{@docRoot}guide/topics/manifest/uses-sdk-element.html"><code><uses-sdk></code></a> 381documentation for more information about how the system handles this attribute.</li> 382</ul> 383 384<p>When declared in an application's manifest, a <code><uses-sdk></code> 385element might look like this: </p> 386 387<pre><manifest> 388 <uses-sdk android:minSdkVersion="5" /> 389 ... 390</manifest></pre> 391 392<p>The principal reason that an application would declare an API Level in 393<code>android:minSdkVersion</code> is to tell the Android system that it is 394using APIs that were <em>introduced</em> in the API Level specified. If the 395application were to be somehow installed on a platform with a lower API Level, 396then it would crash at run-time when it tried to access APIs that don't exist. 397The system prevents such an outcome by not allowing the application to be 398installed if the lowest API Level it requires is higher than that of the 399platform version on the target device.</p> 400 401<p>For example, the {@link android.appwidget} package was introduced with API 402Level 3. If an application uses that API, it must declare a 403<code>android:minSdkVersion</code> attribute with a value of "3". The 404application will then be installable on platforms such as Android 1.5 (API Level 4053) and Android 1.6 (API Level 4), but not on the Android 1.1 (API Level 2) and 406Android 1.0 platforms (API Level 1).</p> 407 408<p>For more information about how to specify an application's API Level 409requirements, see the <a 410href="{@docRoot}guide/topics/manifest/uses-sdk-element.html"><code><uses-sdk></code></a> 411 section of the manifest file documentation.</p> 412 413 414<h2 id="considerations">Development Considerations</h2> 415 416<p>The sections below provide information related to API level that you should 417consider when developing your application.</p> 418 419<h3 id="fc">Application forward compatibility</h3> 420 421<p>Android applications are generally forward-compatible with new versions of 422the Android platform.</p> 423 424<p>Because almost all changes to the framework API are additive, an Android 425application developed using any given version of the API (as specified by its 426API Level) is forward-compatible with later versions of the Android platform and 427higher API levels. The application should be able to run on all later versions 428of the Android platform, except in isolated cases where the application uses a 429part of the API that is later removed for some reason. </p> 430 431<p>Forward compatibility is important because many Android-powered devices 432receive over-the-air (OTA) system updates. The user may install your 433application and use it successfully, then later receive an OTA update to a new 434version of the Android platform. Once the update is installed, your application 435will run in a new run-time version of the environment, but one that has the API 436and system capabilities that your application depends on. </p> 437 438<p>In some cases, changes <em>below</em> the API, such those in the underlying 439system itself, may affect your application when it is run in the new 440environment. For that reason it's important for you, as the application 441developer, to understand how the application will look and behave in each system 442environment. To help you test your application on various versions of the Android 443platform, the Android SDK includes multiple platforms that you can download. 444Each platform includes a compatible system image that you can run in an AVD, to 445test your application. </p> 446 447<h3 id="bc">Application backward compatibility</h3> 448 449<p>Android applications are not necessarily backward compatible with versions of 450the Android platform older than the version against which they were compiled. 451</p> 452 453<p>Each new version of the Android platform can include new framework APIs, such 454as those that give applications access to new platform capabilities or replace 455existing API parts. The new APIs are accessible to applications when running on 456the new platform and, as mentioned above, also when running on later versions of 457the platform, as specified by API Level. Conversely, because earlier versions of 458the platform do not include the new APIs, applications that use the new APIs are 459unable to run on those platforms.</p> 460 461<p>Although it's unlikely that an Android-powered device would be downgraded to 462a previous version of the platform, it's important to realize that there are 463likely to be many devices in the field that run earlier versions of the 464platform. Even among devices that receive OTA updates, some might lag and 465might not receive an update for a significant amount of time. </p> 466 467<h3 id="platform">Selecting a platform version and API Level</h3> 468 469<p>When you are developing your application, you will need to choose 470the platform version against which you will compile the application. In 471general, you should compile your application against the lowest possible 472version of the platform that your application can support. 473 474<p>You can determine the lowest possible platform version by compiling the 475application against successively lower build targets. After you determine the 476lowest version, you should create an AVD using the corresponding platform 477version (and API Level) and fully test your application. Make sure to declare a 478<code>android:minSdkVersion</code> attribute in the application's manifest and 479set its value to the API Level of the platform version. </p> 480 481<h3 id="apilevel">Declaring a minimum API Level</h3> 482 483<p>If you build an application that uses APIs or system features introduced in 484the latest platform version, you should set the 485<code>android:minSdkVersion</code> attribute to the API Level of the latest 486platform version. This ensures that users will only be able to install your 487application if their devices are running a compatible version of the Android 488platform. In turn, this ensures that your application can function properly on 489their devices. </p> 490 491<p>If your application uses APIs introduced in the latest platform version but 492does <em>not</em> declare a <code>android:minSdkVersion</code> attribute, then 493it will run properly on devices running the latest version of the platform, but 494<em>not</em> on devices running earlier versions of the platform. In the latter 495case, the application will crash at runtime when it tries to use APIs that don't 496exist on the earlier versions.</p> 497 498<h3 id="testing">Testing against higher API Levels</h3> 499 500<p>After compiling your application, you should make sure to test it on the 501platform specified in the application's <code>android:minSdkVersion</code> 502attribute. To do so, create an AVD that uses the platform version required by 503your application. Additionally, to ensure forward-compatibility, you should run 504and test the application on all platforms that use a higher API Level than that 505used by your application. </p> 506 507<p>The Android SDK includes multiple platform versions that you can use, 508including the latest version, and provides an updater tool that you can use to 509download other platform versions as necessary. </p> 510 511<p>To access the updater, use the <code>android</code> command-line tool, 512located in the <sdk>/tools directory. You can launch the SDK updater by 513executing <code>android sdk</code>. You can 514also simply double-click the android.bat (Windows) or android (OS X/Linux) file. 515In ADT, you can also access the updater by selecting 516<strong>Window</strong> > <strong>Android SDK 517Manager</strong>.</p> 518 519<p>To run your application against different platform versions in the emulator, 520create an AVD for each platform version that you want to test. For more 521information about AVDs, see <a 522href="{@docRoot}tools/devices/index.html">Creating and Managing Virtual Devices</a>. If 523you are using a physical device for testing, ensure that you know the API Level 524of the Android platform it runs. See the table at the top of this document for 525a list of platform versions and their API Levels. </p> 526 527<h2 id="provisional">Using a Provisional API Level</h2> 528 529<p>In some cases, an "Early Look" Android SDK platform may be available. To let 530you begin developing on the platform although the APIs may not be final, the 531platform's API Level integer will not be specified. You must instead use the 532platform's <em>provisional API Level</em> in your application manifest, in order 533to build applications against the platform. A provisional API Level is not an 534integer, but a string matching the codename of the unreleased platform version. 535The provisional API Level will be specified in the release notes for the Early 536Look SDK release notes and is case-sensitive.</p> 537 538<p>The use of a provisional API Level is designed to protect developers and 539device users from inadvertently publishing or installing applications based on 540the Early Look framework API, which may not run properly on actual devices 541running the final system image.</p> 542 543<p>The provisional API Level will only be valid while using the Early Look SDK 544and can only be used to run applications in the emulator. An application using 545the provisional API Level can never be installed on an Android device. At the 546final release of the platform, you must replace any instances of the provisional 547API Level in your application manifest with the final platform's actual API 548Level integer.</p> 549 550 551<h2 id="filtering">Filtering the Reference Documentation by API Level</h2> 552 553<p>Reference documentation pages on the Android Developers site offer a "Filter 554by API Level" control in the top-right area of each page. You can use the 555control to show documentation only for parts of the API that are actually 556accessible to your application, based on the API Level that it specifies in 557the <code>android:minSdkVersion</code> attribute of its manifest file. </p> 558 559<p>To use filtering, select the checkbox to enable filtering, just below the 560page search box. Then set the "Filter by API Level" control to the same API 561Level as specified by your application. Notice that APIs introduced in a later 562API Level are then grayed out and their content is masked, since they would not 563be accessible to your application. </p> 564 565<p>Filtering by API Level in the documentation does not provide a view 566of what is new or introduced in each API Level — it simply provides a way 567to view the entire API associated with a given API Level, while excluding API 568elements introduced in later API Levels.</p> 569 570<p>If you decide that you don't want to filter the API documentation, just 571disable the feature using the checkbox. By default, API Level filtering is 572disabled, so that you can view the full framework API, regardless of API Level. 573</p> 574 575<p>Also note that the reference documentation for individual API elements 576specifies the API Level at which each element was introduced. The API Level 577for packages and classes is specified as "Since <api level>" at the 578top-right corner of the content area on each documentation page. The API Level 579for class members is specified in their detailed description headers, 580at the right margin. </p> 581 582 583 584 585 586 587 588 589 590