ICO vs QOI: Which Should You Use?

Side-by-side comparison of ICO and QOI image formats — features, pros, cons, and conversion options.

Quick Answer

ICO is best for Website favicons and Windows application icons. QOI is best for Real-time applications requiring fast lossless image encoding.

Quick Verdict

ICO Best for Website favicons and Windows application icons
  • Multiple sizes in one file
  • Transparency support
  • Required for website favicons
  • Limited to small sizes
Convert ICO to QOI →
QOI Best for Real-time applications requiring fast lossless image encoding
  • Extremely fast encode/decode
  • Lossless compression
  • Simple specification
  • Lower compression than PNG
Convert QOI to ICO →

Specs Comparison

Side-by-side technical comparison of ICO and QOI

Feature ICO QOI
Category Image Image
Year Introduced 1985 2021
MIME Type image/x-icon image/qoi
Extensions .ico .qoi
Animation
Hdr
Lossless
Lossy
Max Color Depth 32-bit 8-bit
Transparency

Pros & Cons

ICO

Pros
  • ✓ Multiple sizes in one file
  • ✓ Transparency support
  • ✓ Required for website favicons
Cons
  • ✗ Limited to small sizes
  • ✗ Windows-centric
  • ✗ Outdated for modern web (use PNG/SVG)

QOI

Pros
  • ✓ Extremely fast encode/decode
  • ✓ Lossless compression
  • ✓ Simple specification
Cons
  • ✗ Lower compression than PNG
  • ✗ Very limited adoption
  • ✗ No advanced features

When to Use Each

Choose ICO when...

  • You need files optimized for Website favicons and Windows application icons
  • Multiple sizes in one file
  • Transparency support
  • You need lossless quality

Choose QOI when...

  • You need files optimized for Real-time applications requiring fast lossless image encoding
  • Extremely fast encode/decode
  • Lossless compression
  • You need lossless quality

How to Convert

Convert between ICO and QOI for free on ChangeThisFile

Convert ICO to QOI Runs in your browser — files never leave your device Convert QOI to ICO Runs in your browser — files never leave your device

Frequently Asked Questions

ICO is best for Website favicons and Windows application icons, while QOI is best for Real-time applications requiring fast lossless image encoding. Both are image formats but they differ in compression, compatibility, and intended use cases.

It depends on your use case. ICO is better for Website favicons and Windows application icons. QOI is better for Real-time applications requiring fast lossless image encoding. Consider your specific requirements when choosing between them.

Go to the ICO to QOI converter on ChangeThisFile. The conversion runs entirely in your browser — your file never leaves your device. It's free with no signup required.

Yes. ChangeThisFile supports QOI to ICO conversion. The conversion runs in your browser with no upload required.

File size depends on the content and compression settings. ICO preserves full quality. QOI preserves full quality. For the smallest files, choose the format with lossy compression that meets your quality needs.

ICO and QOI share some features but differ in others. Check the feature comparison table above for a detailed side-by-side breakdown.

Both ICO and QOI are supported file formats that are free to use. You can convert between them for free on ChangeThisFile — browser-based conversions have no limits and your files never leave your device.

QOI is newer — it was introduced in 2021, while ICO dates back to 1985. Newer formats often offer better compression and features, but older formats tend to have wider compatibility.

Related Comparisons

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