QOI to PNG Converter
Convert QOI to PNG in your browser. QOI files usually come from game engines, emulators and tools that want lossless images without a PNG library; PNG is the better fit for screenshots, logos, graphics and anything that needs transparency. You get a lossless 8-bit PNG with full alpha. Nothing is uploaded.
- Processed locally
- No upload, no wait
- No sign-up
- No watermark
Drop images here
or choose files · paste with Ctrl/⌘ V
QOI expected · other image formats also work
How to use QOI to PNG
- 1
Add your QOI files: drop them here, choose them, or paste from the clipboard.
- 2
There is nothing to tune: the PNG is written losslessly. Resizing and rotating are under More options if you need them.
- 3
Click Convert. Each file is decoded and encoded in a background thread on this device.
- 4
Download the .png files one at a time or together as a ZIP.
Why use Aback Images for qoi to png
Where the PNG goes next
PNG opens in every browser, operating system and image editor.
PNG next to QOI
Both sides are lossless, so the size depends on how well the PNG encoder handles this picture compared with the QOI's lossless, byte-aligned run, index, difference and literal codes.
Written without a lossy pass
The PNG is written losslessly, so the pixels decoded from the QOI arrive unchanged.
Processed on your device
Your images are decoded, edited and encoded inside this browser tab by Web Workers. Nothing is uploaded to a server.
QOI vs PNG
What changes from QOI to PNG
Encoding: the QOI uses lossless, byte-aligned run, index, difference and literal codes; PNG uses lossless DEFLATE with a prediction filter chosen per row, and the download is a lossless 8-bit PNG with full alpha.
Bit depth: 8 bits per channel in the QOI; PNG allows 1, 2, 4, 8 or 16 bits per channel, and the PNG written here has 8 bits per channel.
Colour: RGB or RGBA, tagged sRGB or linear in the QOI; PNG supports RGB, greyscale, or an indexed palette of up to 256 colours, written here as 8-bit sRGB.
Transparency: the QOI stores it as a full 8-bit alpha channel; the PNG keeps it as a full alpha channel, so edges and shadows can fade smoothly.
Metadata: the QOI can carry none: a 14-byte header holds only size, channels and colour space; PNG can carry text chunks, an ICC profile, physical resolution and EXIF in an eXIf chunk, but nothing is copied across.
About QOI
QOI is a modern lossless format that encodes 20-50 times faster than PNG with similar file sizes. It is popular in games and tools that value speed and simplicity.
A QOI file is a 14-byte header ('qoif', width, height, channels, colour space), a stream of chunks that each encode a run, an index into 64 recently seen colours, a small difference from the previous pixel or a literal value, and an 8-byte end marker.
QOI files usually come from game engines, emulators and tools that want lossless images without a PNG library.
About PNG
PNG stores pixels losslessly with full alpha transparency. It is ideal for screenshots, logos, UI and anything with sharp edges, but photos saved as PNG are several times larger than JPEG.
A PNG opens with an 8-byte signature and is a chain of chunks, each with its own CRC: IHDR (size, depth, colour type), optional PLTE and tRNS for palettes, one or more IDAT chunks with the compressed rows, and IEND.
When converting QOI to PNG makes sense
PNG is the better choice for screenshots, logos, graphics and anything that needs transparency, while QOI suits fast lossless storage in games and tools.
PNG strengths: Lossless: no quality loss, ever; Full transparency with smooth edges; Perfect for text, screenshots and graphics. Drawbacks to weigh: Large files for photographs; No standard animation (that is APNG).
Limitations
- QOI is lossless, so the pixels you get out are exactly the ones that went in.
- A PNG of a photograph is often several times larger than a JPG; PNG pays off for screenshots, graphics and anything with transparency.
- The PNG is written in full colour; Compress PNG can shrink it further with a palette.
More conversions
Related tools
Convert PNG to QOI in your browser, ready for fast lossless storage in games and tools. Batch, private, no uploads.
Convert any image (HEIC, PNG, WebP, AVIF, RAW, PSD, SVG and 26 more) to PNG in bulk, right in your browser.
Convert JPG to PNG in your browser, ready for screenshots, logos, graphics and anything that needs transparency. Batch, private, no uploads.
Shrink JPG, PNG, WebP, AVIF and GIF files with MozJPEG, OxiPNG and modern codecs, with a live before/after preview.
Resize to exact pixels, a percentage or a longest side, with Lanczos3 and Magic Kernel resampling. Batch ready.
Strip EXIF, GPS, XMP, IPTC and comments losslessly. Pixels are never re-encoded for JPG, PNG and WebP.
Convert between 34 image formats in bulk: HEIC, WebP, AVIF, JPEG XL, PNG, JPG, GIF, TIFF, SVG, ICO, PSD, RAW and more.
Frequently asked questions
Does converting QOI to PNG lose quality?
PNG is written losslessly, so the pixels are stored exactly as decoded.
Is transparency kept in the PNG?
Yes. QOI stores it as a full 8-bit alpha channel, and the PNG is written with an alpha channel, so transparent areas stay transparent.
Which apps open PNG files?
Every browser, operating system and image editor.
Are my images uploaded anywhere?
No. Processing happens inside your browser with WebAssembly and Web Workers. The site only downloads the app code and codecs; your files never leave your device. You can confirm this with the live upload counter on the tool, or in your browser's network panel.
Can I process many files at once?
Yes. Drop a whole selection or folder. Files are processed in parallel on several worker threads, each result can be downloaded on its own, and everything can be saved as one ZIP.
Is it free? Is there a file limit or watermark?
It is free with no account, no watermark and no daily limit. The only limit is your device's memory: very large images (over roughly 100 megapixels) may be refused to keep the tab from crashing.