A simple library for detecting animated images.
Works under Node and Browser environments!
Performant & with small bundle size
Supports GIF, PNG, APNG, WebP and AVIF
Fully typed in Typescript Published under MIT license
> On 01.09.2026 `is-animated` library got massive overhaul and switched the repository it's built from (we're now using fork created by [FRSOURCE team](https://www.frsource.org)).
>
> For more information, see [Migration note](#migration-from-2xx).
## Quick start
### Installation
```bash
npm install is-animated
yarn add is-animated
pnpm add is-animated
```
### Usage in browser
```html
```
```ts
import isAnimated from 'is-animated';
const input = document.querySelector('input[type="file"]');
input.addEventListener('change', async function () {
const arrayBuffer = await this.files[0].arrayBuffer();
const answer = isAnimated(arrayBuffer) ? 'IS' : 'IS NOT';
alert(`File "${this.files[0].name}" ${answer} animated.`);
});
```
> If you prefer, you can import this library using unpkg:
> ``
### Usage in Node.js
```ts
import { readFileSync } from 'fs';
import isAnimated from 'is-animated';
readFileSync('my-test-file.png', (err, buffer) => {
const answer = isAnimated(buffer) ? 'IS' : 'IS NOT';
console.log(`File "my-test-file.png" ${answer} animated.`);
});
```
## Demo
For a working example, check out [our demo](https://www.frsource.org/is-animated#demo).
## Questions
Don’t hesitate to ask a question directly on the [discussion board](https://github.com/FRSOURCE/is-animated/discussions)!
## Changelog
Changes for every release are documented in the [release notes](https://github.com/FRSOURCE/is-animated/releases) and [CHANGELOG file](https://github.com/FRSOURCE/is-animated/tree/main/CHANGELOG.md).
## Migration from 2.x.x
On 01.09.2026 the library got upgraded using source from [FRSOURCE fork](https://github.com/FRSOURCE/is-animated) which also became the new maintenance team!
Version 3:
- adds support for running `is-animated` under browser environment,
- adds support for AVIF format,
- adds support for ESM modules (.mjs),
- drops support for CommonJS,
- drops support for Node below version 20.
Migration path consists of two things: migrate to Node.js >= 20 and switch from CommonJS to ESM.
Everything else (whole API) stays the same. Enjoy!
## Development
1. Check out the repository.
2. Install dependencies using `pnpm i`.
3. Run `pnpm test` to run the test suite.
4. Run `pnpm start` and visit `http://localhost:3000` to see the documentation page. You can test the library using the demo section.
## License
[MIT](https://opensource.org/licenses/MIT) @ 2024-present, [Jakub FRS Freisler](https://www.linkedin.com/in/jakub-freisler-03a32138/), [FRSOURCE](https://www.frsource.org/)
[MIT](https://opensource.org/licenses/MIT) @ 2019-2024, [Józef Sokołowski](https://github.com/qzb)
Forked from [qzb](https://github.com/qzb)'s great library: [is-animated](https://github.com/qzb/is-animated).
---
_Source: https://npm.io/package/is-animated · Machine-readable twin of the npm.io package page. Health data is recomputed on every publish._
