# expressjs/multer

Node.js middleware for handling `multipart/form-data`.

Repository: https://github.com/expressjs/multer
Canonical: https://ross.abutalabs.com/products/multer
Homepage: https://www.npmjs.com/package/multer
Language: JavaScript
License: MIT
License Family: permissive
Last push: 2026-08-25T11:52:43+00:00

## Health v2 (maintenance only)
Score: 92/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 99, release rhythm 77, longevity 100
- inputs: {"age_days": 4598, "days_push": 8, "days_rel": 79, "gap_med": 43, "n_releases_24m": 6}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 12084, forks 1134 (observed 2026-08-28T04:10:51.721606+00:00)

## What it is
Multer is Node.js middleware for handling multipart/form-data, primarily used for file uploads, built on top of busboy. It integrates with Express and adds body and file/files objects to the request.

## Use cases
- handle file uploads in express
- parse multipart form data in node.js
- upload images from html form to server
- accept multiple file uploads with size limits
- process form fields and files together in a post request

## When to choose
- you need to accept file uploads in an Express or Node.js HTTP server
- your forms use multipart/form-data encoding
- you want a lightweight, battle-tested middleware built on busboy

## When to avoid
- your forms are not multipart (e.g. JSON APIs)
- you need direct browser-side file handling
- you want a full-featured upload service with resumable uploads

## Facets
- artifact type: library
- maturity: stable
- function: middleware, file-upload, http-server
- domain: web-development, backend, apis
- platform: -
- tags: express, multipart, form-data, file-handling, busboy, nodejs, web-server

## Member repositories
- expressjs/multer (main) score 92

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:10:51.721606+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 2026-08-29T17:14:57.013698+00:00, confidence not recorded.
  - readme: https://github.com/expressjs/multer (fetched 2026-08-28T04:10:51.721606+00:00, sha 827b16360df7)
  - registry_npm: https://registry.npmjs.org/multer (fetched 2026-08-29T08:12:40.338346+00:00, sha 8b54c4269bbd)
- Data as of 2026-08-30T08:39:29.467469+00:00.