This is a new application, written for today’s machines. It is not a skin on the classic Windows build. What it offers:
A high-performance parallel processing engine sits under 2026.9, and it will be the core of every RIOT optimizer version from here on. There are plans for a web version, a highly performant Linux image optimization server, and likely a cloud-hosted, API-accessible service.
The engine for those future server and cloud versions is built for high throughput, with horizontal scaling when demand requires it. If you are interested in any of these, contact us.
Drop photographs, screenshots, or graphics in and choose an Auto preset — HQ, Standard, Eco, or Lossless. RIOT analyses each file: how many colours it really uses, whether it behaves like a photo or a drawing, how much texture it has, and how hard the original was already compressed. Those signals pick lossless versus lossy encoding, quality, chroma subsampling, and palette size. Manual mode is still there when you want every knob.
Optimization is parallel. The app runs one worker per CPU core so a folder of images is processed together, with a live progress bar, cancel, and a summary of files processed, elapsed time, and bytes saved.
Double-click a file for a curtain compare of original and optimized. Pan, zoom, and drag the split. The preview is encoded with your current settings, not a guess — including animated frames. A hold-to-swap control lets you flip sides instantly. Image info lists attributes for both files side by side.
Only the visible crop is painted each frame, so a 12,000×8,000 photograph pans and zooms as cheaply as a snapshot. Smaller copies for zoomed-out views are built only when needed — fitting the window never pays for work you will not see. Zoomed out, the picture stays smooth; zoomed in past actual size, RIOT shows real pixels. That is faster to draw, and it is how you actually judge compression artifacts.
Open JPEG, PNG, WebP, GIF, TIFF, HEIC, and AVIF. Save to JPEG, PNG, WebP, and GIF. JPEG uses a high-efficiency encoder with progressive scans and careful chroma. PNG offers a slower maximum-compression pass. WebP can be lossless, near-lossless, or lossy. Optimal format tries a smaller container and keeps the source file when it is already smaller. Original format stays in a supported source type.
Resize by pixels or percent, with aspect lock and a choice of resample filter. Quantization (2–256 colours, dither, effort) is available for PNG, WebP, and GIF in manual mode. Metadata can be stripped or kept (EXIF, XMP, IPTC, ICC, and other). Transparency can be preserved, blended to a colour, or made opaque. File handling covers overwrite, backup, delete originals, and original timestamps.
GIF, WebP, and AVIF animations keep their frames unless you ask to flatten to the first frame. Compare plays both sides with each file’s delays.
Light, dark, or system theme. English, Spanish, and Romanian, switchable at runtime. Bug reports and feature ideas go to the User Portal.
RIOT remains free. Work on the tool started in 2004; the first public release was in 2008. Version 2026.9 is the start of the cross-platform line — current, previous, and selected stable builds will stay listed on the download page, each with its changelog.
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