QOI to PCX Converter
Convert QOI to PCX in your browser. QOI files usually come from game engines, emulators and tools that want lossless images without a PNG library; PCX is the better fit for DOS-era software, retro games and old fax or scanner tools. You get a run-length encoded PCX: 8-bit indexed when the image has 256 colours or fewer, otherwise 24-bit RGB. 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 PCX
- 1
Add your QOI files: drop them here, choose them, or paste from the clipboard.
- 2
Pick the colour that replaces transparent areas, since PCX has none.
- 3
Click Convert. Each file is decoded and encoded in a background thread on this device.
- 4
Download the .pcx files one at a time or together as a ZIP.
Why use Aback Images for qoi to pcx
Where the PCX goes next
PCX opens in GIMP, IrfanView, XnView, ImageMagick, Paint Shop Pro and DOSBox-era tools.
PCX next to QOI
Both sides are lossless, so the size depends on how well the PCX encoder handles this picture compared with the QOI's lossless, byte-aligned run, index, difference and literal codes.
Written without a lossy pass
The PCX 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 PCX
What changes from QOI to PCX
Encoding: the QOI uses lossless, byte-aligned run, index, difference and literal codes; PCX uses byte-wise run-length encoding, and the download is a run-length encoded PCX: 8-bit indexed when the image has 256 colours or fewer, otherwise 24-bit RGB.
Bit depth: 8 bits per channel in the QOI; PCX allows 1, 2, 4 or 8 bits per pixel with a palette, or 24-bit as three 8-bit planes, and the PCX written here has 8-bit indexed or 24-bit RGB.
Colour: RGB or RGBA, tagged sRGB or linear in the QOI; PCX supports a 16 or 256-colour palette, or 24-bit RGB, written here as 8-bit sRGB.
Transparency: the QOI stores it as a full 8-bit alpha channel; the PCX has none, so transparent areas are filled with the colour you choose.
Metadata: the QOI can carry none: a 14-byte header holds only size, channels and colour space; PCX can carry only a 128-byte header with the resolution, 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 PCX
PCX is the image format of ZSoft's PC Paintbrush, the standard for DOS paint programs, scanners and games before GIF and BMP took over. It compresses with a simple run-length scheme.
A PCX file has a 128-byte header (the byte 0x0A, version, encoding, bits per pixel, image window, DPI, a 16-colour palette and the number of colour planes), then RLE-compressed scanlines; 256-colour files end with the byte 0x0C and a 768-byte palette.
When converting QOI to PCX makes sense
PCX is the better choice for DOS-era software, retro games and old fax or scanner tools, while QOI suits fast lossless storage in games and tools.
PCX strengths: Read by most legacy and modern viewers; Simple, lossless run-length compression. Drawbacks to weigh: Poor compression for photographs; No transparency; Obsolete outside retro software.
Limitations
- QOI is lossless, so the pixels you get out are exactly the ones that went in.
- PCX's run-length compression suits flat-colour art; photographs barely shrink.
- Transparency is flattened onto the background colour, since PCX has no alpha channel.
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Frequently asked questions
Does converting QOI to PCX lose quality?
PCX is written losslessly, so the pixels are stored exactly as decoded.
What happens to transparency when converting QOI to PCX?
QOI stores transparency as a full 8-bit alpha channel. PCX has no alpha channel, so transparent pixels are composited onto a solid colour, white unless you pick another. To keep transparency, convert to PNG, WebP or AVIF instead.
Which apps open PCX files?
GIMP, IrfanView, XnView, ImageMagick, Paint Shop Pro and DOSBox-era tools. It does not open in web browsers.
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.