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Thumbor

thumbor.org

Free plan LinuxAPISelf-hosted
Visit thumbor.org
Spec score 8.4 #19 of 85 in Image Compression Software

What it is

Thumbor is a self-hosted image service for on-demand cropping, resizing and flipping. Its smart mode looks for faces when choosing a crop and falls back to feature detection if it finds none. Filters can be chained, including brightness, contrast, grayscale, red-eye and blur. Thumbor supports WebP delivery to browsers that can display the format, and its listed capabilities include responsive images, automatic optimization and AVIF support. File, HTTP, Redis and Mongo implementations are available for loaders and storage. The service can be extended with custom filters, storage, loaders, engines, detection and optimizers. A SECURITY_KEY can be used to sign image URLs with HMAC to help guard against tampering. The default HTTP loader uses HTTP; the documentation also describes HTTPS and strict HTTPS options. Thumbor is distributed as a Python package, and current releases require Python 3.10 or newer. The project describes it as open source and lists an MIT license. Its platforms include API, Linux and self-hosted use. The listed plan costs nothing.

Spec sheet

Intended users
The site describes use cases for developers, operations teams, designers, and project managers.Read 9 Oct 2026 · thumbor.org
Free plan
YesRead 20 Sep 2026 · github.com
Headquarters
Rio de Janeiro, BrazilRead 28 Sep 2026 · thumbor.org
Automatic optimization
YesRead 20 Sep 2026 · github.com
AVIF support
YesRead 20 Sep 2026 · github.com
Extensibility
Thumbor supports custom filters, storages, image loaders, engines, detection, and optimizers.Read 9 Oct 2026 · thumbor.readthedocs.io
Filters
Filters can be chained and include brightness, contrast, grayscale, red-eye, and blur.Read 9 Oct 2026 · thumbor.org
HTTPS loading
The documentation says the default HTTP loader uses HTTP and describes HTTPS and strict HTTPS loader options.Read 9 Oct 2026 · thumbor.readthedocs.io
Image formats
Thumbor supports WebP and can serve it to browsers that support the format.Read 9 Oct 2026 · thumbor.org
Image processing
Thumbor provides on-demand image cropping, resizing, and flipping.Read 9 Oct 2026 · thumbor.org
Installation
Thumbor is distributed as a Python package and current releases require Python 3.10 or newer.Read 9 Oct 2026 · thumbor.readthedocs.io
Open source
The project repository describes Thumbor as an open-source photo thumbnail service and lists an MIT license.Read 9 Oct 2026 · github.com
Responsive images
YesRead 20 Sep 2026 · github.com
Security reporting
The security page asks users who find flaws or vulnerabilities to contact the team or create an issue.Read 9 Oct 2026 · thumbor.readthedocs.io
Smart cropping
Smart mode uses face detection first and feature detection if it finds no faces.Read 9 Oct 2026 · thumbor.readthedocs.io
Storage and loaders
The site lists file, HTTP, Redis, and Mongo implementations for loaders and storages.Read 9 Oct 2026 · thumbor.org
URL signing
A SECURITY_KEY can sign image URLs with HMAC to help prevent URL tampering.Read 9 Oct 2026 · thumbor.readthedocs.io
URL transformations
YesRead 20 Sep 2026 · github.com

Plans and prices

Thumbor Free Open-source image service; self-hosted Read 9 Oct 2026 · github.com

Every Thumbor plan and price →

Strong points and limits

Strong points

  • On-demand cropping, resizing and flipping
  • Smart crop checks faces before other features
  • Chainable filters include blur and red-eye
  • Supports WebP and AVIF
  • Extensible with custom loaders and optimizers

Limits

  • Self-hosted deployment is listed
  • Current releases require Python 3.10 or newer
  • Default HTTP loader uses HTTP

Who it suits

Thumbor suits developers, operations teams, designers and project managers who want on-demand image processing in a self-hosted setup. Its extension points may suit teams that need custom loaders, storage or processing components.

Verdict

Thumbor provides a configurable image-processing service for self-hosted use, with multiple storage options and extension points. Its deployment and Python version requirements are relevant when choosing how to run it.

Where Specifiction places it

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