Thumbor
Thumbor is a free, open-source image service for on-demand cropping, resizing, and flipping, with URL transformations and automatic optimization.
What Thumbor is
Thumbor is a free, open-source image service for on-demand cropping, resizing, and flipping, with URL transformations and automatic optimization. Its smart crop mode looks for faces before falling back to feature detection. You can chain filters such as brightness, contrast, grayscale, red-eye, and blur, and serve WebP images to browsers that support the format. The listed loaders and storage implementations cover file, HTTP, Redis, and Mongo. Developers can extend Thumbor with custom filters, loaders, storages, engines, detection, and optimizers. A SECURITY_KEY can be used to sign image URLs with HMAC to help prevent tampering. The default HTTP loader uses HTTP; HTTPS and strict HTTPS loader options are also described. Thumbor is distributed as a Python package, and current releases require Python 3.10 or newer. It supports API, Linux, and self-hosted use, and the project lists an MIT license. The service is free, with a listed plan price of no cost.
Good
- Free, open-source image service.
- On-demand cropping, resizing, and flipping.
- Smart cropping prioritizes face detection.
- Chained filters include brightness and blur.
- Custom components support extensive extension.
Watch out
- Current releases require Python 3.10 or newer.
- Default HTTP loader uses HTTP.
- Self-hosted platform option requires managing your setup.
Who it suits
Thumbor suits developers and operations teams who want to manage image processing in a self-hosted setup. Designers and project managers are also among its stated intended users.
Verdict
Thumbor brings on-demand image processing and extensibility to a free self-hosted service. Check the Python requirement and loader options against your setup.
Plans and prices
From Thumbor's own pricing page, checked 9 Oct 2026.
| Plan | Price | What it gives you |
|---|---|---|
| Thumbor | Free | Open-source image service; self-hosted |
The facts
Each one read from Thumbor's own pages, with the date it was checked.
What it does
- Automatic optimization
- Yeschecked 20 Sep 2026
- AVIF support
- Yeschecked 20 Sep 2026
- Extensibility
- Thumbor supports custom filters, storages, image loaders, engines, detection, and optimizers.checked 9 Oct 2026
- Filters
- Filters can be chained and include brightness, contrast, grayscale, red-eye, and blur.checked 9 Oct 2026
- HTTPS loading
- The documentation says the default HTTP loader uses HTTP and describes HTTPS and strict HTTPS loader options.checked 9 Oct 2026
- Image formats
- Thumbor supports WebP and can serve it to browsers that support the format.checked 9 Oct 2026
- Image processing
- Thumbor provides on-demand image cropping, resizing, and flipping.checked 9 Oct 2026
- Installation
- Thumbor is distributed as a Python package and current releases require Python 3.10 or newer.checked 9 Oct 2026
- Intended users
- The site describes use cases for developers, operations teams, designers, and project managers.checked 9 Oct 2026
- Open source
- The project repository describes Thumbor as an open-source photo thumbnail service and lists an MIT license.checked 9 Oct 2026
- Responsive images
- Yeschecked 20 Sep 2026
- Security reporting
- The security page asks users who find flaws or vulnerabilities to contact the team or create an issue.checked 9 Oct 2026
- Smart cropping
- Smart mode uses face detection first and feature detection if it finds no faces.checked 9 Oct 2026
- Storage and loaders
- The site lists file, HTTP, Redis, and Mongo implementations for loaders and storages.checked 9 Oct 2026
- URL signing
- A SECURITY_KEY can sign image URLs with HMAC to help prevent URL tampering.checked 9 Oct 2026
- URL transformations
- Yeschecked 20 Sep 2026
Money
- Free plan
- Yeschecked 20 Sep 2026
The company
- Headquarters
- Rio de Janeiro, Brazilchecked 28 Sep 2026
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