QOI(Quite OK Image Format)は高速でシンプルな可逆圧縮形式です。実装が数百行と軽く、エンコードもデコードも PNG より圧倒的に速いのが特徴です。
Typical use: とにかく速く可逆で保存したいときに QOI を使います。
About the QOI format
QOI(Quite OK Image Format)は高速でシンプルな可逆形式です。実装が数百行と軽く、エンコードもデコードも PNG より圧倒的に速いのが特徴です。
圧縮率は PNG にやや劣ります。速さを優先する用途に向きます。
Strengths
- ✓ とにかく速い
- ✓ 実装が極めて簡単
- ✓ 可逆で画質劣化なし
Limitations
- ✗ PNG よりは大きい
- ✗ 対応ソフトが少ない
- Compression
- Lossless (RLE/delta)
- Transparency
- Supported
- Animation
- Not supported
- Metadata
- None
- Best for
- Hobby engines, lossless simplicity
Convert QOI to…
53 direct directions plus 15 workflows, sorted A–Z; 🔥 marks popular targets.
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Frequently asked questions
What is a QOI file?
QOI (Quite OK Image) is a 2022 lossless format with a ~200-line spec — PNG-class simplicity that compresses similarly fast.
How do I convert QOI files online?
Pick a target format from the "Convert QOI to…" list below, drop your file and hit convert. Everything runs in your browser — no install, no upload, no watermark, no limits.
Is it safe to convert QOI files here?
Yes. Every conversion is performed by your own device inside the browser — files never leave for a server, and the page keeps working even offline.
Which formats can QOI convert to?
This page lists all 68 directions across documents, images, audio, video, spreadsheets and archives — each one is its own free converter page.