JPEG to QOI Converter
Processing entirely on your device — large files may take a moment.
JPEG is the proper full name of the format most people call JPG — the Joint Photographic Experts Group standard. Files ending in .jpeg are identical to .jpg files in every way. QOI is popular with hobbyist engines and emulators; convert to PNG to view it anywhere.
Because the whole conversion happens on your device, it is instant, unlimited and genuinely private — no accounts, no watermarks, no files on anyone's server. Multiple files are converted in one go.
How JPEG compares to QOI
| JPEG | QOI | |
|---|---|---|
| Compression | Lossy (DCT, adjustable quality) | Lossless (RLE/delta) |
| Transparency | Not supported | Supported |
| Animation | Not supported | Not supported |
| Metadata | EXIF, ICC profile | None |
| Best for | Photos and continuous-tone images | Hobby engines, lossless simplicity |
How to convert JPEG to QOI
- 1
Select your files
Drag & drop your JPEG files onto the area above, or click to browse. You can add multiple files at once for batch conversion.
- 2
Convert instantly
Click "Convert to QOI". The conversion runs entirely inside your browser using WebAssembly — no upload, no queue, no waiting.
- 3
Download results
Download each converted QOI file individually, or grab everything at once as a ZIP archive.
About the JPEG format
JPG (short for JPEG, the Joint Photographic Experts Group committee that standardized it in 1992) has been the default photo format for over three decades. It compresses photographs using the discrete cosine transform: the image is split into 8×8 blocks, and details the human eye is bad at noticing are discarded. The result is files many times smaller than uncompressed data, at a quality level you control when saving.
In practice JPG is unbeatable for photographs and smooth gradients — camera memory cards, messaging apps and the web all assume it. It is a poor fit for screenshots, logos or anything with sharp edges and flat color, where compression leaves visible ringing around text. There is no transparency support, color depth is capped at 8 bits per channel, and every re-save with compression compounds tiny generational losses.
+ Strengths
- ✓Opens on literally every device, app and browser made in the last 30 years
- ✓Compresses photos dramatically — typically 10:1 or better with little visible loss
- ✓Quality level is adjustable, so you can trade fidelity for file size
- ✓Mature ecosystem: EXIF metadata, ICC profiles and progressive loading all supported
! Limitations
- −Lossy — artifacts appear on text, sharp edges and flat areas
- −No transparency, so overlays and logos need PNG or WebP instead
- −Repeated re-saving at low quality permanently degrades the image
About the QOI format
QOI (Quite OK Image, 2021) is a lossless format defined in one short specification document: a stream of simple run-length and delta ops over linear pixels. An encoder fits in 300 lines, decodes faster than PNG, and compresses comparably for photographic content.
It has found a home in emulators, demoscene projects and hobby engines — anywhere people want images without a codec dependency. Viewers rarely support it, so converting QOI to PNG is the way to bring these files into normal tools.
+ Strengths
- ✓Radically simple spec (~200 lines)
- ✓Lossless with fast decode
- ✓No patent or licensing questions
! Limitations
- −Almost no viewer support
- −Larger than modern codecs for many images
Why convert JPEG to QOI?
Think of it as moving your file to the container that fits the job. Lossy — artifacts appear on text, sharp edges and flat areas QOI works differently: Radically simple spec (~200 lines) If any of that sounds like your task, run the conversion — it takes seconds and nothing leaves your device.
Frequently asked questions
Is this JPEG to QOI converter really free?
Yes — completely free, with no sign-up, no watermark and no daily conversion limits. The site is supported by advertising.
Are my files uploaded to a server?
No. The conversion runs entirely inside your browser using WebAssembly, so your files never leave your device — that is what makes it instant and private.
Does it work on Windows, Mac, iPhone and Android?
Yes. Anything with a modern browser works: Windows, macOS, Linux, Android and iOS. No software installation is required.
Will I lose quality converting JPEG to QOI?
No — QOI is a lossless format, so every pixel of the converted image matches your original JPEG file. You can also adjust the quality/size balance before converting when the target format supports compression.
Will transparent areas survive the conversion to QOI?
Transparency is kept whenever QOI actually supports an alpha channel. If the target format has none (like JPG), transparent areas are flattened onto a white background — that is a property of the format, not of this tool.
Can I convert several JPEG files at once?
Yes — drop as many files as you like into the tool and they are converted in one batch. When more than one file comes out, everything is bundled into a ZIP for a single download.