 Thomas Steiner [GitHub](https://github.com/tomayac) [LinkedIn](https://www.linkedin.com/in/thomassteinerlinkedin) [Mastodon](https://toot.cafe/@tomayac) [Bluesky](https://bsky.app/profile/tomayac.com) [Homepage](https://blog.tomayac.com/)
Published: November 11, 2024, Last updated: July 30, 2025
Browser Support
- ' d='M96 183a64 64 0 0 1-23-23L17 64a128 128 0 0 0 111 192l55-96a64 64 0 0 1-87 23Z'/%3E%3Cpath fill='url(%23b)' d='M192 128a64 64 0 0 1-9 32l-55 96A128 128 0 0 0 239 64H128a64 64 0 0 1 64 64Z'/%3E%3Ccircle cx='128' cy='128' r='52' fill='%231a73e8'/%3E%3Cpath fill='url(%23c)' d='M96 73a64 64 0 0 1 32-9h111a128 128 0 0 0-222 0l56 96a64 64 0 0 1 23-87Z'/%3E%3C/svg%3E)
- ' xlink:href='%23A'%3E%3Cstop offset='.76' stop-opacity='0'/%3E%3Cstop offset='.95' stop-opacity='.5'/%3E%3Cstop offset='1'/%3E%3C/radialGradient%3E%3CradialGradient id='F' cx='2523' cy='4680' r='20243' gradientTransform='matrix(-.03715 .99931 -2.12836 -.07913 13579 3530)' xlink:href='%23A'%3E%3Cstop offset='0' stop-color='%2335c1f1'/%3E%3Cstop offset='.11' stop-color='%2334c1ed'/%3E%3Cstop offset='.23' stop-color='%232fc2df'/%3E%3Cstop offset='.31' stop-color='%232bc3d2'/%3E%3Cstop offset='.67' stop-color='%2336c752'/%3E%3C/radialGradient%3E%3CradialGradient id='G' cx='24247' cy='7758' r='9734' gradientTransform='matrix(.28109 .95968 -.78353 .22949 24510 -16292)' xlink:href='%23A'%3E%3Cstop offset='0' stop-color='%2366eb6e'/%3E%3Cstop offset='1' stop-color='%2366eb6e' stop-opacity='0'/%3E%3C/radialGradient%3E%3Cpath id='H' d='M24105 20053a9345 9345 0 01-1053 472 10202 10202 0 01-3590 646c-4732 0-8855-3255-8855-7432 0-1175 680-2193 1643-2729-4280 180-5380 4640-5380 7253 0 7387 6810 8137 8276 8137 791 0 1984-230 2704-456l130-44a12834 12834 0 006660-5282c220-350-168-757-535-565z'/%3E%3Cpath id='I' d='M11571 25141a7913 7913 0 01-2273-2137 8145 8145 0 01-1514-4740 8093 8093 0 013093-6395 8082 8082 0 011373-859c312-148 846-414 1554-404a3236 3236 0 012569 1297 3184 3184 0 01636 1866c0-21 2446-7960-8005-7960-4390 0-8004 4166-8004 7820 0 2319 538 4170 1212 5604a12833 12833 0 007684 6757 12795 12795 0 003908 610c1414 0 2774-233 4045-656a7575 7575 0 01-6278-803z'/%3E%3Cpath id='J' d='M16231 15886c-80 105-330 250-330 566 0 260 170 512 472 723 1438 1003 4149 868 4156 868a5954 5954 0 003027-839 6147 6147 0 001133-850 6180 6180 0 001910-4437c26-2242-796-3732-1133-4392-2120-4141-6694-6525-11668-6525-7011 0-12703 5635-12798 12620 47-3654 3679-6605 7996-6605 350 0 2346 34 4200 1007 1634 858 2490 1894 3086 2921 618 1067 728 2415 728 2952s-271 1333-780 1990z'/%3E%3Cuse fill='url(%23B)' xlink:href='%23H'/%3E%3Cuse fill='url(%23D)' opacity='.35' xlink:href='%23H'/%3E%3Cuse fill='url(%23C)' xlink:href='%23I'/%3E%3Cuse fill='url(%23E)' opacity='.4' xlink:href='%23I'/%3E%3Cuse fill='url(%23F)' xlink:href='%23J'/%3E%3Cuse fill='url(%23G)' xlink:href='%23J'/%3E%3C/svg%3E)
- ' gradientUnits='userSpaceOnUse'%3E%3Cstop offset='.2' stop-color='%239059ff' stop-opacity='0'/%3E%3Cstop offset='.3' stop-color='%238c4ff3' stop-opacity='.1'/%3E%3Cstop offset='.8' stop-color='%237716a8' stop-opacity='.5'/%3E%3Cstop offset='1' stop-color='%236e008b' stop-opacity='.6'/%3E%3C/radialGradient%3E%3CradialGradient id='ff-g' cx='239.1' cy='34.6' r='171.6' gradientUnits='userSpaceOnUse'%3E%3Cstop offset='0' stop-color='%23ffe226'/%3E%3Cstop offset='.1' stop-color='%23ffdb27'/%3E%3Cstop offset='.3' stop-color='%23ffc82a'/%3E%3Cstop offset='.5' stop-color='%23ffa930'/%3E%3Cstop offset='.7' stop-color='%23ff7e37'/%3E%3Cstop offset='.8' stop-color='%23ff7139'/%3E%3C/radialGradient%3E%3CradialGradient id='ff-h' cx='374' cy='-74.3' r='732.2' gradientUnits='userSpaceOnUse'%3E%3Cstop offset='.1' stop-color='%23fff44f'/%3E%3Cstop offset='.5' stop-color='%23ff980e'/%3E%3Cstop offset='.6' stop-color='%23ff5634'/%3E%3Cstop offset='.7' stop-color='%23ff3647'/%3E%3Cstop offset='.9' stop-color='%23e31587'/%3E%3C/radialGradient%3E%3CradialGradient id='ff-i' cx='304.6' cy='7.1' r='536.4' gradientTransform='rotate(84 303 4)' gradientUnits='userSpaceOnUse'%3E%3Cstop offset='0' stop-color='%23fff44f'/%3E%3Cstop offset='.1' stop-color='%23ffe847'/%3E%3Cstop offset='.2' stop-color='%23ffc830'/%3E%3Cstop offset='.3' stop-color='%23ff980e'/%3E%3Cstop offset='.4' stop-color='%23ff8b16'/%3E%3Cstop offset='.5' stop-color='%23ff672a'/%3E%3Cstop offset='.6' stop-color='%23ff3647'/%3E%3Cstop offset='.7' stop-color='%23e31587'/%3E%3C/radialGradient%3E%3CradialGradient id='ff-j' cx='235' cy='98.1' r='457.1' gradientUnits='userSpaceOnUse'%3E%3Cstop offset='.1' stop-color='%23fff44f'/%3E%3Cstop offset='.5' stop-color='%23ff980e'/%3E%3Cstop offset='.6' stop-color='%23ff5634'/%3E%3Cstop offset='.7' stop-color='%23ff3647'/%3E%3Cstop offset='.9' stop-color='%23e31587'/%3E%3C/radialGradient%3E%3CradialGradient id='ff-k' cx='355.7' cy='124.9' r='500.3' gradientUnits='userSpaceOnUse'%3E%3Cstop offset='.1' stop-color='%23fff44f'/%3E%3Cstop offset='.2' stop-color='%23ffe141'/%3E%3Cstop offset='.5' stop-color='%23ffaf1e'/%3E%3Cstop offset='.6' stop-color='%23ff980e'/%3E%3C/radialGradient%3E%3ClinearGradient id='ff-a' x1='446.9' y1='76.8' x2='47.9' y2='461.8' gradientUnits='userSpaceOnUse'%3E%3Cstop offset='.1' stop-color='%23fff44f'/%3E%3Cstop offset='.1' stop-color='%23ffe847'/%3E%3Cstop offset='.2' stop-color='%23ffc830'/%3E%3Cstop offset='.4' stop-color='%23ff980e'/%3E%3Cstop offset='.4' stop-color='%23ff8b16'/%3E%3Cstop offset='.5' stop-color='%23ff672a'/%3E%3Cstop offset='.5' stop-color='%23ff3647'/%3E%3Cstop offset='.7' stop-color='%23e31587'/%3E%3C/linearGradient%3E%3ClinearGradient id='ff-l' x1='442.1' y1='74.8' x2='102.6' y2='414.3' gradientUnits='userSpaceOnUse'%3E%3Cstop offset='.2' stop-color='%23fff44f' stop-opacity='.8'/%3E%3Cstop offset='.3' stop-color='%23fff44f' stop-opacity='.6'/%3E%3Cstop offset='.5' stop-color='%23fff44f' stop-opacity='.2'/%3E%3Cstop offset='.6' stop-color='%23fff44f' stop-opacity='0'/%3E%3C/linearGradient%3E%3C/defs%3E%3Cpath d='M479 166c-11-25-32-52-49-60a249 249 0 0 1 25 73c-27-68-73-95-111-155a255 255 0 0 1-8-14 44 44 0 0 1-4-9 1 1 0 0 0 0-1 1 1 0 0 0-1 0c-60 35-81 101-83 134a120 120 0 0 0-66 25 71 71 0 0 0-6-5 111 111 0 0 1-1-58c-25 11-44 29-58 44-9-12-9-52-8-60l-8 4a175 175 0 0 0-24 21 210 210 0 0 0-22 26 203 203 0 0 0-32 73l-1 2-2 15a229 229 0 0 0-4 34v1a240 240 0 0 0 477 40l1-9c5-41 0-84-15-121zM202 355l3 1-3-1zm55-145zm198-31z' fill='url(%23ff-a)'/%3E%3Cpath d='M479 166c-11-25-32-52-49-60 14 26 22 53 25 72v1a207 207 0 0 1-206 279c-113-3-212-87-231-197-3-17 0-26 2-40-2 11-3 14-4 34v1a240 240 0 0 0 477 40l1-9c5-41 0-84-15-121z' fill='url(%23ff-b)'/%3E%3Cpath d='M479 166c-11-25-32-52-49-60 14 26 22 53 25 72v1a207 207 0 0 1-206 279c-113-3-212-87-231-197-3-17 0-26 2-40-2 11-3 14-4 34v1a240 240 0 0 0 477 40l1-9c5-41 0-84-15-121z' fill='url(%23ff-c)'/%3E%3Cpath d='m362 195 1 1a130 130 0 0 0-22-29C266 92 322 5 331 0c-60 35-81 101-83 134l9-1c45 0 84 25 105 62z' fill='url(%23ff-d)'/%3E%3Cpath d='M257 210c-1 6-22 26-29 26-68 0-80 41-80 41 3 35 28 64 57 79l4 2 7 3a107 107 0 0 0 31 6c120 6 143-143 57-186 22-4 45 5 58 14-21-37-60-62-105-62l-9 1a120 120 0 0 0-66 25l17 16c16 16 58 33 58 35z' fill='url(%23ff-e)'/%3E%3Cpath d='M257 210c-1 6-22 26-29 26-68 0-80 41-80 41 3 35 28 64 57 79l4 2 7 3a107 107 0 0 0 31 6c120 6 143-143 57-186 22-4 45 5 58 14-21-37-60-62-105-62l-9 1a120 120 0 0 0-66 25l17 16c16 16 58 33 58 35z' fill='url(%23ff-f)'/%3E%3Cpath d='m171 151 5 3a111 111 0 0 1-1-58c-25 11-44 29-58 44 1 0 36 0 54 11z' fill='url(%23ff-g)'/%3E%3Cpath d='M18 261a242 242 0 0 0 231 197 207 207 0 0 0 206-279c8 56-20 110-64 146-86 71-169 43-186 31l-3-1c-50-24-71-70-67-110-42 0-57-35-57-35s38-28 89-4c46 22 90 4 90 4 0-2-42-19-58-35l-17-16a71 71 0 0 0-6-5l-5-3c-18-11-52-11-54-11-9-12-9-51-8-60l-8 4a175 175 0 0 0-24 21 210 210 0 0 0-22 26 203 203 0 0 0-32 73c0 1-9 38-5 57z' fill='url(%23ff-h)'/%3E%3Cpath d='M341 167a130 130 0 0 1 22 29 46 46 0 0 1 4 3c55 50 26 121 24 126 44-36 72-90 64-146-27-68-73-95-111-155a255 255 0 0 1-8-14 44 44 0 0 1-4-9 1 1 0 0 0 0-1 1 1 0 0 0-1 0c-9 5-65 92 10 167z' fill='url(%23ff-i)'/%3E%3Cpath d='M367 199a46 46 0 0 0-4-3l-1-1c-13-9-36-18-58-15 86 44 63 193-57 187a107 107 0 0 1-31-6 131 131 0 0 1-11-5c17 12 99 39 186-31 2-5 31-76-24-126z' fill='url(%23ff-j)'/%3E%3Cpath d='M148 277s12-41 80-41c7 0 28-20 29-26s-44 18-90-4c-51-24-89 4-89 4s15 35 57 35c-4 40 16 85 67 110l3 1c-29-15-54-44-57-79z' fill='url(%23ff-k)'/%3E%3Cpath d='M479 166c-11-25-32-52-49-60a249 249 0 0 1 25 73c-27-68-73-95-111-155a255 255 0 0 1-8-14 44 44 0 0 1-4-9 1 1 0 0 0 0-1 1 1 0 0 0-1 0c-60 35-81 101-83 134l9-1c45 0 84 25 105 62-13-9-36-18-58-14 86 43 63 192-57 186a107 107 0 0 1-31-6 131 131 0 0 1-11-5l-3-1 3 1c-29-15-54-44-57-79 0 0 12-41 80-41 7 0 28-20 29-26 0-2-42-19-58-35l-17-16a71 71 0 0 0-6-5 111 111 0 0 1-1-58c-25 11-44 29-58 44-9-12-9-52-8-60l-8 4a175 175 0 0 0-24 21 210 210 0 0 0-22 26 203 203 0 0 0-32 73l-1 2-2 15a279 279 0 0 0-4 34v1a240 240 0 0 0 477 40l1-9c5-41 0-84-15-121zm-24 13z' fill='url(%23ff-l)'/%3E%3C/svg%3E)
- ' xlink:href='%23s-b'%3E%3Cstop offset='0' stop-color='%2324a5f3' stop-opacity='0' /%3E%3Cstop offset='1' stop-color='%231e8ceb' /%3E%3C/radialGradient%3E%3CradialGradient id='s-j' cx='109.3' cy='13.8' r='93.1' gradientTransform='matrix(-.02 1.1 -1.04 -.02 137 -115)' xlink:href='%23s-b'%3E%3Cstop offset='0' stop-opacity='0' /%3E%3Cstop offset='1' stop-color='%235488d6' stop-opacity='0' /%3E%3Cstop offset='1' stop-color='%235d96eb' /%3E%3C/radialGradient%3E%3C/defs%3E%3Crect width='220' height='220' x='22' y='-107' fill='url(%23s-a)' ry='49' transform='matrix(.57 0 0 .57 187 256)' /%3E%3Cg transform='translate(194 190)'%3E%3Ccircle cx='67.8' cy='67.7' fill='url(%23s-c)' paint-order='stroke fill markers' r='54' /%3E%3Ccircle cx='-69.9' cy='69.3' fill='url(%23s-i)' transform='translate(138 -2)' r='54' /%3E%3C/g%3E%3Cellipse cx='120' cy='14.2' fill='url(%23s-j)' rx='93.1' ry='93.7' transform='matrix(.58 0 0 .58 192 250)' /%3E%3Cg transform='matrix(.58 0 0 .57 197 182)'%3E%3Cpath fill='%23cac7c8' d='M46 192h1l72-48-7-9-66 57Z' /%3E%3Cpath fill='%23fbfffc' d='M46 191v1l66-57-7-9-59 65Z' /%3E%3Cpath fill='url(%23s-d)' d='m119 144-7-9 66-57-59 66Z' /%3E%3Cpath fill='%23fb645c' d='m105 126 7 9 66-57-1-1-72 49Z' /%3E%3C/g%3E%3Cpath stroke='%23fff' stroke-linecap='round' stroke-miterlimit='1' stroke-width='1.3' d='m287 278 3-2m-12-17 8-2m-8-3h4m-4-13 8 2m-8 3h4m-1-13 7 3m-4-11 7 4m-2-11 6 6m0-12 6 7m1-11 4 6m4-10 3 7m5-9 2 7m15-7-1 7m10-5-3 7m11-4-4 7m11-2-5 6m16 7-7 4m10 4-7 3m10 6-8 1m8 16-8-2m5 10-7-3m4 11-7-4m2 11-6-5m0 11-5-6m-2 11-4-7m-4 11-3-8m-6 10-1-8m-16 8 2-8m-10 5 3-7m-11 4 4-7m-11 2 5-6m-8 3 3-3m4 8 2-3m5 8 2-4m6 7 1-4m8 5v-4m8 4v-4m9 3-1-4m9 1-2-4m9 0-2-4m9-2-3-3m8-4-3-2m8-5-4-2m7-6-4-1m5-8h-4m4-8h-4m3-9-4 1m1-9-4 2m-1-9-3 2m-2-9-3 3m-4-8-2 3m-5-8-2 4m-6-6-1 3m-8-5v4m-8-4v4m-9-2 1 3m-9 0 2 3m-9 1 2 3m-9 2 3 3m-8 4 3 2m-8 5 4 2m-7 6 4 1m-4 25 4-1m-2 5 7-3m-6 7 4-2m-2 6 7-4m-13-21h8m41-41v-8m0 99v-8m49-42h-8' transform='translate(-65 8)' /%3E%3C/svg%3E)
[Source](https://developer.mozilla.org/docs/Web/API/Summarizer)
You can offer your users the ability to distill lengthy articles, complex
documents, or even lively chat conversations into concise and insightful
summaries.
The Summarizer API can be used to generate different types of summaries in
varied lengths and formats, such as sentences, paragraphs, bullet point lists,
and more. We believe this API is useful in the following scenarios:
- Summarizing the key points of an article or a chat conversation.
- Suggesting titles and headings for articles.
- Creating a concise and informative summary of a lengthy text.
- Generating a teaser for a book based on a book review.
> [!IMPORTANT]
> **Important** : The built-in foundation model is a generative AI model. Before you build with APIs that use it, you should review the [People + AI Guidebook](https://pair.withgoogle.com/guidebook/) for best practices, methods, and examples for designing with AI.
## Get started
The Summarizer API is available from [Chrome 138 stable](https://chromestatus.com/roadmap).
Run feature detection to see if the browser supports the Summarizer API.
```javascript
if ('Summarizer' in self) {
// The Summarizer API is supported.
}
```
> [!TIP]
> **Tip:** Use the [@types/dom-chromium-ai](https://www.npmjs.com/package/@types/dom-chromium-ai) npm package to get TypeScript typings for the Prompt API and other built-in AI APIs for easier access in your codebase.
### Review the hardware requirements
The following requirements exist for developers and the users who operate features using these
APIs in Chrome. Other browsers may have different operating requirements.
The **Language Detector** and **Translator APIs** work in Chrome on
desktop. These APIs do not work on mobile devices.
The **Prompt API** , **Summarizer API** , **Writer API** ,
**Rewriter API** , and **Proofreader API** work in Chrome when the
following conditions are met:
- **Operating system** : Windows 10 or 11; macOS 13+ (Ventura and onwards); Linux; or ChromeOS (from Platform 16389.0.0 and onwards) on [Chromebook Plus](https://www.google.com/chromebook/chromebookplus/) devices. Chrome for Android, iOS, and ChromeOS on non-Chromebook Plus devices are not yet supported by the APIs which use foundation models.
- **Storage** : At least 22 GB of free space on the volume that contains your Chrome profile.
> [!NOTE]
> Built-in models should be significantly smaller. The exact size may vary slightly with updates.
- **GPU or CPU** : Built-in models can run with GPU or CPU.
- **GPU**: Strictly more than 4 GB of VRAM.
- **CPU**: 16 GB of RAM or more and 4 CPU cores or more.
- **Note**: The Prompt API with audio input requires a GPU.
- **Network** : Unlimited data or an unmetered connection.
> [!IMPORTANT]
> **Key term** : A [metered connection](https://support.microsoft.com/windows/metered-connections-in-windows-7b33928f-a144-b265-97b6-f2e95a87c408) is a data-limited internet connection. Wi-Fi and ethernet connections tend to be unmetered by default, while cellular connections are often metered.
> [!NOTE]
> **Note**: The network requirement is only for the initial download of the model. Subsequent use of the model does not require a network connection. No data is sent to Google or any third party when using the model.
Gemini Nano's exact size may vary as the browser updates the model. To determine the current size, visit `chrome://on-device-internals`.
> [!NOTE]
> **Note**: If the available storage space falls to less than 10 GB after the download, the model is removed from your device. The model redownloads once the requirements are met.
### Model download
The Summarizer API uses a model trained to generate high-quality
summaries. The API is built into Chrome and is downloaded
the first time a website uses this API.
> [!IMPORTANT]
> **Important** : The built-in foundation model is a generative AI model. Before you build with APIs that use it, you should review the [People + AI Guidebook](https://pair.withgoogle.com/guidebook/) for best practices, methods, and examples for designing with AI.
To determine if the model is ready to use, call the asynchronous
[`Summarizer.availability()`](https://developer.chrome.com/docs/ai/get-started.md.txt#model-download) function.
If the response to `availability()` is `downloadable`, listen for download
progress to inform the user of its progress, as it may take time.
```javascript
const availability = await Summarizer.availability();
```
To trigger the model download and create the summarizer, check for
[user activation](https://developer.chrome.com/docs/ai/get-started.md.txt#user-activation), then call
the asynchronous `Summarizer.create()` function.
```javascript
// Proceed to request batch or streaming summarization
const summarizer = await Summarizer.create({
monitor(m) {
m.addEventListener('downloadprogress', (e) => {
console.log(`Downloaded ${e.loaded * 100}%`);
});
}
});
```
## API functions
The `create()` function lets you configure a new summarizer object to your
needs. It takes an optional `options` object with the following parameters:
- `sharedContext`: Additional shared context that can help the summarizer.
- `type`: The type of the summarization, with the allowed values `key-points` (default), `tldr`, `teaser`, and `headline`. See the following table for details.
- `format`: The format of the summarization, with the allowed values `markdown` (default) and `plain-text`.
- `length`: The length of the summarization, with the allowed values `short` (default), `medium`, and `long`. The meanings of these lengths vary depending on the `type` requested. For example, in Chrome's implementation, a short key-points summary consists of three bullet points, and a short summary is one sentence.
- `preference`: A mechanism for developers to indicate whether they prioritize fast execution or comprehensive capabilities.
- `auto`: The browser balances execution speed with summarization capability and may dynamically adjust its internal processing based on the environment, system constraints, or context.
- `speed`: The browser should prioritize low latency and fast execution. This approach prioritizes performance, which may limit the summarization capability, potentially resulting in less nuanced extraction or simpler synthesis of the source text.
- `capability`: The browser should prioritize the comprehensiveness and coherence of the summarization, and a model that offers more flexibility in terms of summary types and other configurable options. This approach focuses on accurately capturing subtle context and producing highly refined summaries, which may result in higher latency and slower execution speeds.
Once set, the parameters can't be changed. Create a new summarizer object
if you need to make modifications to the parameters.
The following table demonstrates the different types of summaries and their
corresponding lengths. The lengths represent the maximum possible value, as
sometimes, the results can be shorter.
Type Meaning Length `"tldr"` Summary should be short and to the point, providing a quick overview of the input, suitable for a busy reader. short 1 sentence medium 3 sentences long 5 sentences `"teaser"` Summary should focus on the most interesting or intriguing parts of the input, designed to draw the reader in to read more. short 1 sentence medium 3 sentences long 5 sentences `"key-points"` Summary should extract the most important points from the input, presented as a bulleted list. short 3 bullet points medium 5 bullet points long 7 bullet points `"headline"` Summary should effectively contain the main point of the input in a single sentence, in the format of an article headline. short 12 words medium 17 words long 22 words
For example, you could initialize a summarizer to output a medium length of
key points in Markdown.
```javascript
const options = {
sharedContext: 'This is a scientific article',
type: 'key-points',
format: 'markdown',
length: 'medium',
monitor(m) {
m.addEventListener('downloadprogress', (e) => {
console.log(`Downloaded ${e.loaded * 100}%`);
});
}
};
const availability = await Summarizer.availability();
if (availability === 'unavailable') {
// The Summarizer API isn't usable.
return;
}
// Check for user activation before creating the summarizer
if (navigator.userActivation.isActive) {
const summarizer = await Summarizer.create(options);
}
```
### Assign expected languages
The Summarizer API accepts `"en"`, `"ja"`, `"es"`, `"de"`, and `"fr"`. Support
for additional languages is in development.\`"Set the expected input, output,
and context languages, when creating your session. This allows the browser to
reject the request, if the browser cannot support a specific language
combination.
```javascript
const summarizer = await Summarizer.create({
type: 'key-points',
expectedInputLanguages: ['en', 'ja', 'es'],
outputLanguage: 'es',
expectedContextLanguages: ['en'],
sharedContext: 'These are requests to summarize articles from a multilanguage newspaper. The users expect a response in Spanish.',
});
```
There are two ways to run the summarizer: streaming and batch (request-based
output).
### Batch summarization
With batch summarization, the model processes the input as a whole and
then produces the output.
To get a batch summary, call the `summarize()` function. The first
argument is the text that you want to summarize. The second, optional argument
is an object with a `context` field. This field lets you add background details
that might improve the summarization.
```javascript
const longText = document.querySelector('article').innerHTML;
const summary = await summarizer.summarize(longText, {
context: 'This article is intended for a tech-savvy audience.',
});
```
> [!TIP]
> **Tip:** Remove any unnecessary data, including HTML markup, when summarizing. For content present on a webpage, you can use the [`innerText`](https://developer.mozilla.org/docs/Web/API/Element/innerText) property of an HTML element, as this property represents only the rendered text content of an element and its descendants.
### Stream summarization
[Streaming](https://developer.chrome.com/docs/ai/streaming.md.txt) summarization offers results in real-time.
The output updates continuously as the input is added and adjusted. To get a
streaming summary, call `summarizeStreaming()` instead of `summarize()`.
```javascript
const longText = document.querySelector('article').innerHTML;
const stream = summarizer.summarizeStreaming(longText, {
context: 'This article is intended for junior developers.',
});
for await (const chunk of stream) {
console.log(chunk);
}
```
## Demo
You can try the Summarizer API in the
[Summarizer API Playground](https://chrome.dev/web-ai-demos/summarization-api-playground/).
## Permission Policy, iframes, and Web Workers
By default, the Summarizer API is only available to top-level windows and to their
same-origin iframes. Access to the API can be delegated to cross-origin iframes
using the Permission Policy `allow=""` attribute:
```html
```
The Summarizer API isn't available in Web Workers for now. This is due to the
complexity of establishing a responsible document for each worker, in order to
check the Permissions Policy status.
## Share feedback
We want to see what you're building with the Summarizer API. Share your
websites and web applications with us on [X](https://x.com/ChromiumDev),
[YouTube](https://www.youtube.com/user/ChromeDevelopers), and
[LinkedIn](https://www.linkedin.com/showcase/chrome-for-developers/).
For feedback on Chrome's implementation, file a
[bug report](https://issues.chromium.org/issues/new?component=1617227&priority=P2&type=bug&template=0&noWizard=true)
or a [feature request](https://issues.chromium.org/issues/new?component=1617227&priority=P2&type=feature_request&template=0&noWizard=true).