Import mapsBaseline · Widely available
A <script type="importmap"> HTML element provides an import map as a JSON string. An import map controls how the browser should resolve module specifiers when importing JavaScript modules.
Supported in all major browsers for at least 30 months — safe to use without fallbacks. Baseline since Mar 27, 2023. Widely available since Sep 27, 2025.
Browser support
DesktopChrome
1–88Not supported
89+Supportedsince Mar 2, 2021
Current: 155Edge
12–88Not supported
89+Supportedsince Mar 4, 2021
Current: 154Firefox
1–107Not supported
108+Supportedsince Dec 13, 2022
Current: 157Safari
1–16.3Not supported
16.4+Supportedsince Mar 27, 2023
Current: 27MobileChrome Android
18–88Not supported
89+Supportedsince Mar 2, 2021
Current: 155Firefox Android
4–107Not supported
108+Supportedsince Dec 13, 2022
Current: 157Safari iOS
1–16.3Not supported
16.4+Supportedsince Mar 27, 2023
Current: 27How to use
This feature is Baseline widely available — use it freely, no fallback needed.
Example
HTML
<script type="importmap">
{
"imports": {
"lodash": "https://cdn.jsdelivr.net/npm/lodash-es@4.17.21/lodash.js"
}
}
</script>
<script type="module">
import { debounce } from "lodash";
</script>Feature detection
JS · check before using
if ("type" in document.createElement("script")) {
// the type attribute/property of <script> is supported
}