RIOT
RIOT optimizes images with batch processing and live comparison for JPEG, PNG, WebP, and GIF formats.
About RIOT
RIOT is a desktop image optimizer for macOS, Windows, and Linux. It reduces file size for JPEG, PNG, WebP, and GIF images, and it can process whole folders in batches. The homepage describes it as free and states that it has been available since 2008. Its homepage describes image optimization as staying on the user's machine. The homepage does not mention cloud processing, but this entry makes no guarantee about privacy.
The app can choose compression settings automatically by analyzing each picture, or the user can set them manually. Before writing a batch to disk, a live curtain comparison shows the original and optimized versions side by side, including the current format and quality settings. Batch progress can be cancelled and is summarized when the batch finishes. The homepage lists the current builds as macOS for Apple Silicon, 64-bit Windows, and 64-bit Linux (AppImage and .deb). Pricing is not confirmed in the source.
Key features
- Batch processing that runs one optimization worker per CPU core
- Live, cancellable progress with a summary of images, time, and bytes saved
- Side-by-side curtain compare of original and optimized images with pan and zoom
- Automatic analysis that selects lossless, near-lossless, or lossy encoding settings
- Animated GIF, WebP, and AVIF frames kept through optimization and compare playback
- Option to strip or preserve EXIF, XMP, IPTC, and ICC metadata
Best for: People who compress large numbers of photos or graphics on a desktop and want to check results before saving.
Good for
- Batches are processed in parallel across CPU cores rather than one file at a time.
- The comparison preview lets users check results before writing a batch to disk.
- Automatic settings can be overridden with manual control.
Watch out for
- The current macOS build is listed for Apple Silicon only.
- The current Windows and Linux builds are listed as 64-bit only.
RIOT at a glance
- Website
- riot-optimizer.com
- Category
- Online Tools › Image Tools
- Type
- Online tool
- Pricing
- Not confirmed. Check the site
- Platforms
- Linux, macOS, Web, Windows
- Open source
- Not stated
- Language
- English
- Last checked
- Oct 6, 2026 · Online when checked
- Listed
- Oct 5, 2026
Guides for Image Tools
RIOT alternatives
Tools and sites you could use instead, ranked by how closely they match.
YOGA Image Optimizer converts and optimizes JPEG, PNG, and WebP images.
Converseen converts, resizes, and processes images in batches across Windows, Linux, macOS, and FreeBSD.
pingo optimizes PNG, JPEG, WebP, and APNG images using lossless or lossy compression.
JPEGView views and edits JPEG, BMP, PNG, WebP, TGA, GIF, and TIFF images with configurable processing tools.
Resize multiple images in a batch with Bulk Image Resize, which processes files without uploading them.
Caesium is a free, open-source online image compression tool with batch processing and preview options.
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RIOT FAQ
Does the preview reflect the settings I choose?
Yes. The preview follows the current format and quality settings, including animated frames, so results can be judged before a batch is written to disk.
Can original files be backed up during a batch?
File handling includes options for overwrite, backup, deleting originals, and keeping timestamps. A confirmation step appears before destructive options run.
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