OpenAnyFile
The short version: QOI is a Quite OK Image from Dominic Szablewski. The longer version — including the quirk that trips most people up — is below, along with a viewer that runs entirely on your own device.
Quite OK Image is an image format developed by Dominic Szablewski, first appearing in 2021. It is normally produced by Game tooling, embedded and hobby projects.
The entire specification fits on one page. It encodes and decodes several times faster than PNG while landing at a comparable lossless size, which is the whole reason it exists.
| Full name | Quite OK Image |
|---|---|
| File category | Images |
| MIME type | image/qoi |
| Magic bytes (file signature) | 71 6F 69 66 (qoif) |
| Developer | Dominic Szablewski |
| Introduced | 2021 |
| Usually created by | Game tooling, embedded and hobby projects |
| OpenAnyFile engine | progressive image decoder |
| Opens without upload | Yes — parsed locally in your browser |
OpenAnyFile routes .qoi to its progressive image decoder, which renders the picture drawn natively if your browser ships a decoder for this codec, and a full byte-level inspection with the detected signature if it does not.
Viewing, inspecting and verifying. You get the picture drawn natively if your browser ships a decoder for this codec, and a full byte-level inspection with the detected signature if it does not. File details, exact byte size and the detected signature are always shown.
Guaranteed rendering. Whether the picture draws depends on whether your browser ships a decoder for this codec; when it does not, you still get the full byte-level inspection instead of an error.
The entire pipeline — detection, decoding, rendering — runs client-side. Your browser hands the bytes to a decoder compiled to WebAssembly, the result is drawn to the page, and that is the whole journey. No account is created, no file is stored, and no analytics event carries your filename. This is also why there is no size limit imposed by a server: the only ceiling is your own available memory.
Yes. OpenAnyFile's progressive image decoder runs in your browser, so you can read a QOI file with nothing installed. You get the picture drawn natively if your browser ships a decoder for this codec, and a full byte-level inspection with the detected signature if it does not. For full editing you still need the original application — this is a viewer, not an editor.
Look at the first bytes rather than the extension. A genuine QOI begins with 71 6F 69 66 (qoif). Opening the file in OpenAnyFile shows that signature in the file-details panel, so a file renamed to .qoi by mistake is easy to spot.
With OpenAnyFile, yes, because nothing is uploaded. The file is read locally through your browser's File API and never leaves your device, so there is no server copy to leak, log or retain. That matters most for the kind of file people are least willing to hand to a random converter site.
Quite OK Image — an image/qoi format created by Dominic Szablewski since 2021. The entire specification fits on one page. It encodes and decodes several times faster than PNG while landing at a comparable lossless size, which is the whole reason it exists.
Yes — the same engine also opens .emf, .exr, .hdr, so you can compare related files without switching tools.
These open with the same engine, so if you have one of these sitting next to your .qoi file, it will open too: