# Rich-Harris/shimport

Use JavaScript modules in all browsers, including dynamic imports

Repository: https://github.com/Rich-Harris/shimport
Canonical: https://ross.abutalabs.com/products/shimport
Homepage: https://shimport-demos.surge.sh
Language: JavaScript
License: MIT
License Family: permissive
Last push: 2024-06-26T08:57:15+00:00

## Health v2 (maintenance only)
Score: 32/100 (v2, computed 2026-09-02T17:46:02.011165+00:00)
- activity 0, release rhythm 35, longevity 100
- inputs: {"age_days": 2929, "days_push": 798, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: no_releases
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1235, forks 34 (observed 2026-08-28T04:04:04.972689+00:00)

## What it is
Shimport is a 2kb browser shim that implements JavaScript ES module import/export syntax, including dynamic import(), for browsers lacking native module support. It transforms module code at runtime and exposes a small global API for loading and transforming modules.

## Use cases
- use ES modules in browsers without native module support
- load JavaScript modules with dynamic import() in legacy browsers
- fallback module loader when feature detection fails
- run ES modules inside web workers
- serve Rollup ESM code-split output to all browsers

## When to choose
- you must support old browsers that lack native ES module or dynamic import support
- you want a tiny runtime shim instead of a full transpile-to-AMD/UMD build pipeline
- you need to load ESM bundles in web workers on legacy engines

## When to avoid
- your target browsers all support native ES modules and dynamic import
- you need full language transpilation beyond import/export syntax
- you want a maintained bundler-integrated solution rather than a runtime shim

## Facets
- artifact type: library
- maturity: maintenance
- function: parser, developer-tools
- domain: web-development, frontend
- platform: browser
- tags: es-modules, shim, polyfill, dynamic-import, browser-compatibility, browsers, web-server

## Member repositories
- Rich-Harris/shimport (main) score 32

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:04:04.972689+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-30T08:22:03.047895+00:00, confidence not recorded.
  - readme: https://github.com/Rich-Harris/shimport (fetched 2026-08-28T04:04:04.972689+00:00, sha b37713176ef4)
  - registry_npm: https://registry.npmjs.org/shimport (fetched 2026-08-29T12:21:23.090252+00:00, sha 49f894b27f0d)
- Data as of 2026-08-30T08:39:29.467469+00:00.