File uploader

Uploading files middleware for NodeJS, Express, TrinteJS, Connect.

Installation

npm install express-uploader

The package ships with TypeScript declarations (dist/index.d.ts) — no separate @types/... install is required.

Requirements

• Node.js >= 18.0.0
• An upstream multipart parser on req.files (e.g. multer) for form uploads, or an XHR client setting x-file-name / x-file-size headers for streaming uploads.
• GraphicsMagick (the gm CLI binary) on the host — only required if resize, crop, or thumbnails is enabled.

Development

For development, after cloning the repository, install dependencies and run the test suite:

$ npm ci
$ npm test

The default test command runs vitest run.

Useful maintainer commands:

$ npm run build
$ npm run example          # build, then start the example server on 127.0.0.1:3000
$ npm run lint
$ npm run typecheck

CI and release automation

GitHub Actions uses .github/workflows/unit-tests.yml for test automation. The workflow runs on push and pull_request, installs dependencies with npm ci, and then runs npm run typecheck, npm run lint, and npm test on Node.js 22 and 24.

Publishing is handled by .github/workflows/publish.yml. The publish workflow runs only for pushed tags that match v*, uses the protected GitHub environment named npm-publish, installs npm ^11.5.1, runs npm ci, runs npm test, checks package contents with npm publish --dry-run, and then runs npm publish.

The npm publish path uses GitHub Actions OIDC Trusted Publishing. Do not add NODE_AUTH_TOKEN, NPM_TOKEN, or a registry-url setting to this workflow. Before the first release tag is pushed, configure npm Trusted Publishing for package express-uploader with repository biggora/express-uploader, workflow .github/workflows/publish.yml, and environment npm-publish.

Usage overview

for TrinteJS

manual setup in project config/routes.js

var Uploader = require('express-uploader');

module.exports = function routes(map) {
    ...
    map.all('/upload', function(req, res, next) {
        var uploader = new Uploader({
            debug: true,
            validate: true,
            thumbnails: true,
            thumbToSubDir: true,
            tmpDir: __dirname + '/tmp',
            publicDir: __dirname + '/public',
            uploadDir: __dirname + '/public/files',
            uploadUrl: '/files/',
            thumbSizes: [140, [100, 100]]
        });
        uploader.uploadFile(req, function(data) {
            res.send(JSON.stringify(data), {'Content-Type': 'text/plain'}, 200);
        });
    });
};

for ExpressJS

var Uploader = require('express-uploader');

app.all('/upload', function (req, res, next) {
  var uploader = new Uploader({
    debug: true,
    validate: true,
    thumbnails: true,
    thumbToSubDir: true,
    tmpDir: __dirname + '/tmp',
    publicDir: __dirname + '/public',
    uploadDir: __dirname + '/public/files',
    uploadUrl: '/files/',
    thumbSizes: [140, [100, 100]],
  });
  uploader.uploadFile(req, function (data) {
    res.send(JSON.stringify(data), { 'Content-Type': 'text/plain' }, 200);
  });
});

TypeScript / ES modules

import express from 'express';
import multer from 'multer';
import Uploader, { UploadResult } from 'express-uploader';

const app = express();
const parseMultipart = multer({ dest: `${__dirname}/tmp` });

const uploader = new Uploader({
  uploadDir: `${__dirname}/public/files`,
  uploadUrl: '/files/',
  validate: true,
  maxFileSize: 10_000_000,
});

app.post('/upload', parseMultipart.any(), (req, res) => {
  uploader.uploadFile(req, (data) => {
    if (Array.isArray(data)) {
      const successes = (data as UploadResult[]).filter((f) => f.success);
      res.json({ uploaded: successes });
    } else {
      res.status(400).json(data);
    }
  });
});

NestJS (Express platform)

The express-uploader/nest subpath exports a DynamicModule and an injectable UploaderService that wraps the core's callback API in a Promise. The adapter targets @nestjs/platform-express only.

Install the Nest peers alongside the package:

npm install @nestjs/common @nestjs/core @nestjs/platform-express reflect-metadata

Register the module:

// app.module.ts
import { Module } from '@nestjs/common';
import { UploaderModule } from 'express-uploader/nest';
import { UploadController } from './upload.controller';

@Module({
  imports: [
    UploaderModule.forRoot({
      tmpDir: '/tmp/uploads',
      uploadDir: '/var/www/files',
      uploadUrl: '/files/',
      thumbnails: true,
      thumbSizes: [[100, 100], 200],
    }),
  ],
  controllers: [UploadController],
})
export class AppModule {}

Use it from a controller — multer is wired the standard Nest way via FilesInterceptor:

// upload.controller.ts
import { Controller, Post, Req, UseInterceptors } from '@nestjs/common';
import { FilesInterceptor } from '@nestjs/platform-express';
import type { Request as ExpressRequest } from 'express';
import { UploaderService } from 'express-uploader/nest';

@Controller('upload')
export class UploadController {
  constructor(private readonly uploader: UploaderService) {}

  @Post()
  @UseInterceptors(FilesInterceptor('files', 10))
  async handle(@Req() req: ExpressRequest) {
    return this.uploader.upload(req);
  }
}

UploaderService.upload(req) returns a Promise that never rejects — per-file errors surface as success: false on each UploadResult, matching the core's contract.

UploaderModule.forRootAsync({ useFactory, inject, imports }) is also available for config-driven setups.

Next.js (Pages Router)

The express-uploader/next subpath exports a withUploader(options) HOF that returns a NextApiHandler. It embeds multer, shims req.xhr / req.header(), and exposes onSuccess / onError hooks. App Router is not supported.

Install the Next peers:

npm install next multer

Create the API route:

// pages/api/upload.ts
import { withUploader } from 'express-uploader/next';

export const config = {
  api: { bodyParser: false }, // multer must own the request stream
};

export default withUploader({
  uploadDir: './public/files',
  uploadUrl: '/files/',
  thumbnails: true,
  thumbSizes: [[100, 100]],
  multerLimits: { fileSize: 10 * 1024 * 1024 },
  fieldName: 'files', // omit to accept any field name
  onSuccess: (result, _req, res) => {
    res.status(201).json({ ok: true, result });
  },
  onError: (err, _req, res) => {
    res.status(400).json({ ok: false, error: err.message });
  },
});

Defaults when hooks are omitted: 200 JSON on success, 500 JSON on pipeline error. GET (and anything other than POST/PUT) returns 405 with an Allow: POST, PUT header.

tmpDir defaults to os.tmpdir()/express-uploader if not provided — the core's __dirname/tmp default would point inside node_modules, which is read-only on most serverless deploys.

Removing files

uploader.removeFile('avatar.txt', () => {
  // file at uploadDir/avatar.txt has been deleted (if it existed)
});

removeFile runs the same name sanitization as uploads, so .. traversal and absolute paths are rejected.

Callback result shape

The shape of data depends on how the upload arrived:

• Form upload (req.files populated by a multipart parser such as multer) — data is UploadResult[], one entry per file. Use Array.isArray(data) to detect this branch.
• XHR streaming upload (req.xhr === true, x-file-name / x-file-size headers) — data is a single UploadResult object. On invalid headers or stream errors, it carries success: false and an error message.
• Empty request (no files attached) — data is a single synthetic UploadResult with error: 'Not files found!'.

Options

| Name | Type | Default | Description | | --------------- | ------- | ------------------------------------- | -------------------------------------------------------------------------------------------------- | | debug | boolean | false | Enable verbose logging via console.log. | | safeName | boolean | true | Sanitize filenames and avoid collisions; disable to keep the originally provided name. | | validate | boolean | false | Apply minFileSize / maxFileSize / acceptFileTypes checks before moving the file. | | quality | number | 80 | JPEG quality (0–100) used when resizing/cropping via GraphicsMagick. | | thumbnails | boolean | false | Generate thumbnails for image uploads. | | thumbToSubDir | boolean | false | When true, thumbnails go to uploadDir/<WxH>/<name>; otherwise to uploadDir/thumb_..._<name>. | | tmpDir | string | <module>/tmp | Temp directory for incoming uploads. Created if missing. | | publicDir | string | <module>/public | Public root. Created if missing. | | uploadDir | string | <module>/public/files | Final destination directory. Created if missing. | | uploadUrl | string | /files/ | URL prefix used to build UploadResult.url. A trailing / is added automatically. | | maxPostSize | integer | 11000000 | Maximum total bytes accepted on the XHR streaming path (≈ 110 MB). | | minFileSize | integer | 1 | Minimum bytes per file when validate is on. | | maxFileSize | integer | 10000000 | Maximum bytes per file when validate is on (≈ 100 MB). | | acceptFileTypes | RegExp | /.+/i | Allow-list filename regex when validate is on. | | imageTypes | RegExp | /\.(gif\|jpe?g\|png)$/i | Filename regex used to decide whether GraphicsMagick should be invoked. | | inlineFileTypes | RegExp | /\.(gif\|jpe?g\|png)$/i | Reserved for downstream consumers; not currently used by the middleware itself. | | thumbSizes | array | [[100, 100]] | Thumbnail sizes. Each entry is either a single number (max dimension) or [width, height]. | | resize | boolean | false | Resize image uploads to newSize while moving them. | | newSize | tuple | [800, 600] | Target [width, height] for resize. Pass only the first element to keep aspect ratio. | | crop | boolean | false | Crop image uploads using coordinates while moving them. | | coordinates | object | { width:800, height:600, x:0, y:0 } | Crop region (in pixels) for crop. | | osSep | string | path.sep | Deprecated. Retained for backwards compatibility; paths now use Node's path module. |

In the Wild

The following projects use express-uploader.

If you are using express-uploader in a project, app, or module, get on the list below by getting in touch or submitting a pull request with changes to the README.

Author

Aleksej Gordejev ([email protected]).

License

(The MIT License)

Copyright (c) 2012 Aleksej Gordejev [email protected]

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the 'Software'), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

Resources

• Visit the author website.
• Follow @biggora on Twitter for updates.
• Report issues on the github issues page.