imagor

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What imagor is

imagor is an open-source image processing server and Go library for transforming images through URL-based requests. It supports cropping, resizing, fitting, padding, smart crop, filters, and format conversion. Supported output formats include JPEG, PNG, GIF, WebP, AVIF, JXL, TIFF, and JP2, with quality controls. Its URL syntax follows thumbor, and the project positions it as a high-performance replacement. imagor uses libvips through the vipsgen Go binding, with streaming for parallel processing pipelines; its documentation says it is typically 4–8x faster than the quickest ImageMagick settings. It runs as an HTTP server and has first-class Docker support. Built-in storage adaptors cover HTTP(S), proxy, file systems, AWS S3, Google Cloud Storage, and S3-compatible services including Cloudflare R2, MinIO, and DigitalOcean Spaces. Production security guidance recommends requiring signed URLs with IMAGOR_SECRET, restricting source hosts, expiring URLs, and setting image-size limits. The companion imagorvideo adds video thumbnail extraction, while imagorface provides self-hosted face detection, redaction, and a metadata endpoint. The default URL-signing algorithm is SHA1 HMAC; the documentation recommends SHA256 or SHA512 instead.

Who it suits

imagor suits developers and teams that need a self-hosted HTTP image transformation server or Go library. It is especially relevant to projects using Docker, cloud storage, or URL-based image processing and wanting control over source restrictions and request limits.

What it does well

Supports cropping, resizing, fitting, padding, smart crop, and filters.
Converts images to formats including WebP, AVIF, and TIFF.
Docker support and multiple built-in storage adaptors are available.
Security guidance covers signed URLs, expiry, and source restrictions.
imagorface performs face detection self-hosted without third-party API calls.

What to know first

Production use requires configuring signed URLs to avoid unsafe access.
The default signing algorithm is SHA1 HMAC, which the docs advise replacing.
The video thumbnail feature is provided by a companion project.

Getting started

Visit https://docs.imagor.net/.
Deploy imagor as an HTTP server, with Docker support available.
Configure an image source using a supported storage adaptor.
Set IMAGOR_SECRET and use signed request URLs for production.
Set source restrictions and image-size limits for your deployment.

Verdict

Choose imagor if you want an open-source, self-hosted image server with URL-based transformations, storage adaptors, and configurable security controls. Look elsewhere if you need image processing without managing server deployment or security configuration.

Questions

Is imagor open source?

Yes. imagor is open source.

What image transformations does imagor support?

It supports cropping, resizing, fitting, padding, smart crop, filters, and format conversion.

Can imagor be self-hosted?

Yes. It runs as an HTTP server and offers first-class Docker support.

Which storage services can imagor use?

Built-in adaptors support HTTP(S), proxy, file systems, AWS S3, Google Cloud Storage, and S3-compatible services including Cloudflare R2, MinIO, and DigitalOcean Spaces.

Does imagor support video thumbnails?

The imagorvideo companion project adds video thumbnail extraction through ffmpeg C bindings.

What should I know about URL signing?

Production guidance recommends signed URLs using IMAGOR_SECRET. The default is SHA1 HMAC, and the docs recommend SHA256 or SHA512 instead.

Facts from imagor's own pages

Deployment: imagor is an HTTP server with first-class Docker support. · docs.imagor.net, 9 Oct 2026
Face detection: The imagorface companion supports face-centred smart crop, face redaction and a metadata endpoint, with detection performed self-hosted and without third-party API calls. · docs.imagor.net, 9 Oct 2026
Filters: The filter pipeline includes image transforms such as blur, watermark, format conversion, and text overlay. · docs.imagor.net, 9 Oct 2026
Image engine: imagor uses libvips with the vipsgen Go binding and implements libvips streaming for parallel processing pipelines. · docs.imagor.net, 9 Oct 2026
Image limits: Configurable resolution, width and height limits reject oversized images before processing. · docs.imagor.net, 9 Oct 2026
Image processing: It supports URL-based cropping, resizing, fitting, padding, smart crop, filters, and format conversion. · docs.imagor.net, 9 Oct 2026
Limits: The docs note that the default URL-signing algorithm is SHA1 HMAC and recommend SHA256 or SHA512 because SHA1 is not considered cryptographically secure today. · docs.imagor.net, 9 Oct 2026
Performance: imagor uses libvips through vipsgen and implements streaming for parallel processing pipelines and high network throughput. · docs.imagor.net, 9 Oct 2026
Pricing: The official docs provide no pricing information for imagor. · docs.imagor.net, 9 Oct 2026
Product: imagor is a fast, secure image processing server and Go library. · docs.imagor.net, 9 Oct 2026
Purpose: imagor is a fast image processing server and Go library. · docs.imagor.net, 9 Oct 2026
Resource limits: The security guide documents image resolution limits, request and loader timeouts, processing concurrency caps, and a queue size that can return HTTP 429 when full. · docs.imagor.net, 9 Oct 2026
Security: The security guide recommends requiring signed URLs with IMAGOR_SECRET in production and warns that IMAGOR_UNSAFE disables signature verification. · docs.imagor.net, 9 Oct 2026
Source restrictions: The HTTP Loader can restrict source hosts with allowlists, lock loading to a base URL, or refuse plain HTTP sources. · docs.imagor.net, 9 Oct 2026
Speed: The docs say imagor is typically 4–8x faster than the quickest ImageMagick settings. · docs.imagor.net, 9 Oct 2026
Storage integrations: Built-in adaptors support HTTP(S), proxy, file system, AWS S3 and Google Cloud Storage; S3-compatible options include Cloudflare R2, MinIO and DigitalOcean Spaces. · docs.imagor.net, 9 Oct 2026
Support: imagor remains open source, with bugs and feature requests handled through GitHub Issues; optional commercial support is provided independently by Adrian C. Shum. · docs.imagor.net, 9 Oct 2026
Transformations: Its image endpoint supports cropping, resizing, fitting, padding, and smart crop. · docs.imagor.net, 9 Oct 2026
URL compatibility: imagor adopts thumbor URL syntax as a high-performance drop-in replacement. · docs.imagor.net, 9 Oct 2026
URL expiry: Signed URLs can use the expire filter, and requests with an expired timestamp are rejected even if the signature is valid. · docs.imagor.net, 9 Oct 2026
URL security: The security guide recommends setting IMAGOR_SECRET to require HMAC-signed request URLs in production. · docs.imagor.net, 9 Oct 2026
Video: The imagorvideo companion adds video thumbnail extraction through ffmpeg C bindings and sends the selected frame through imagor’s image pipeline. · docs.imagor.net, 9 Oct 2026
Video extension: The docs describe imagorvideo as an adjacent project that adds video thumbnail capability through ffmpeg C bindings. · docs.imagor.net, 9 Oct 2026

Where imagor stands on Freedom251

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