---
area: "Learn"
parent: "Extensions chapter"
url: "https://unpoly.com/learn/legacy-browsers"
---
# Supporting legacy browsers
Unpoly's standard build supports all modern browsers. Older browsers get a working, non-enhanced app through graceful degradation, and a transpiled build covers old build tools.
## Browsers supported by default {#baseline}
Recent versions of the evergreen browsers (Chrome, Firefox, Microsoft Edge) are supported, as are the last two major versions of Safari. See [`up.framework.isSupported()`](https://unpoly.com/api/up.framework.isSupported.md) for how Unpoly checks the current browser.
On a browser it cannot support, Unpoly does not boot and does not [enhance](https://unpoly.com/learn/enhancing-elements.md) the page. Links and forms fall back to default browser behavior, leaving you with a classic server-side application.
## ES6 build {#es6-build}
`unpoly.js` uses ES2024 syntax that very old browsers or build tools may not support. If you're not already working around this with a transpiler like [Babel](https://babeljs.io/), you can use the ES6 build of Unpoly:
| Development | Production |
| --- | --- |
| [`unpoly.es6.js`](https://cdn.jsdelivr.net/npm/unpoly@3.15.0/unpoly.es6.js) | [`unpoly.es6.min.js`](https://cdn.jsdelivr.net/npm/unpoly@3.15.0/unpoly.es6.min.js) (62.3 KB gzipped) |
The ES6 build does not contain any polyfills. When a target browser is missing an API that Unpoly uses, you need to load a polyfill yourself.
## Internet Explorer {#internet-explorer}
The last version with support for Internet Explorer 11 is [2.7](https://unpoly.com/changes/2.7.1.md).