What is a .QOI file?
QOI is a simple, fast lossless image format.
- Did you know
- QOI appeared in 2021 as a tiny format that compresses about as well as PNG but far faster.
- QOI was invented by Dominic Szablewski, who donated the specification to the public domain under CC0 so anyone can implement it freely.
- Its whole specification fits on a single page, and the author claimed encoding 20 to 50 times faster than PNG at similar file sizes.
- What Analyser reads
- Decode and preview extra still-image formats in pure JavaScript - Truevision TGA, QOI, Netpbm (PPM/PGM/PBM), PCX, farbfeld, WBMP, XBM/XPM, Sun Raster and SGI are fully rendered - and read header metadata from codec-heavy formats: Radiance HDR, DirectDraw Surface (DDS) game textures, OpenEXR, JPEG 2000, JPEG XR, EPS/PostScript, Windows WMF/EMF metafiles, Apple ICNS icons, CUR/ANI cursors, MNG and Lottie animations.
- Depth of analysis
- .QOI is an identification-grade format: Analyser recognises it from its bytes and decodes the header metadata it carries, rather than opening it in a full viewer. Formats that do get a full viewer are marked "Full" on the formats page.
- Open a .QOI file
- Drag a .QOI file onto the Analyser home page (or tap to pick one). It is identified entirely in your browser - nothing is uploaded, there is no account, and it works offline once installed.