ICO Converter
Convert and optimize images for different uses with this ico converter. Transform images between formats while maintaining quality.
When to Use This Tool
Creating favicon.ico files for websites from existing images.
Key Benefits
- Required for browser tab icons
- Multiple sizes in one file
- Universal browser support
- Professional website appearance
Pro Tip
Include 16x16, 32x32, and 48x48 pixel versions in your ICO file for best display.
Supported Formats
| Format | Best For | Supports |
|---|---|---|
| JPEG | Photos | Lossy compression |
| PNG | Graphics, screenshots | Transparency, lossless |
| WebP | Web images | Both lossy and transparency |
| GIF | Animations | Limited colors |
Optimization Tips
1. Use JPEG for photos to reduce file size 2. Choose PNG when you need transparency 3. Consider WebP for modern browsers 4. Compress images before uploading to websites
Format Comparison
| PNG | ICO | |
|---|---|---|
| Compression | Lossless (DEFLATE) | Container — holds BMP or PNG payloads |
| Transparency | Full 8-bit alpha channel | Yes, via a PNG payload |
| Animation | No (APNG is a separate, patchily supported extension) | No |
| Browser support | Universal since 2001 | Universal for favicons |
| Best for | Screenshots, logos, line art, anything with sharp edges or transparency | favicon.ico, which browsers still request from the site root by default |
Serving the Right Format
``html
`
The browser takes the first source it can decode, so ordering matters: smallest format
first, universally supported fallback last. Always set width and height — without
them the page reflows when the image loads, which is a Cumulative Layout Shift penalty.
Sizing Before Compressing
Resizing beats compressing. Halving an image's dimensions removes 75% of its pixels, which
no quality setting can match, and a 4000px photo displayed at 800px is wasting 96% of what
it downloads.
| Displayed at | Serve (1×) | Serve (2× for retina) |
|---|---|---|
| 400px | 400px | 800px |
| 800px | 800px | 1600px |
| 1200px | 1200px | 2400px |
Above 2× there is no visible benefit on any current display, and the file size keeps rising.Quality Settings That Hold Up
| Setting | Looks | Use for |
|---|---|---|
| 95–100 | Indistinguishable, large | Masters and print |
| 80–90 | Very good | Hero images, product photography |
| 70–80 | Good | Most web content |
| 50–70 | Visible artefacts on detail | Thumbnails |
| Below 50 | Obvious | Nothing |
Around 75–85 is where the curve bends: below it quality falls quickly, above it file size
rises quickly for no visible gain.Everything Runs Locally
Conversion and compression here use a canvas in your own tab. No file is uploaded, nothing
is stored, and the work continues offline once the page has loaded. That is worth knowing
for anything containing faces, documents or unreleased work — most online image tools upload
by necessity, because they process server-side.
Getting the Rest of the Win
Serve modern formats with a fallback.with AVIF, then WebP, then JPG.Always setwidthandheight.Without them the page reflows on load, which
Google measures as Cumulative Layout Shift.
Lazy-load below the fold — and never the hero, sinceloading="lazy"` on it delays
- Strip metadata. EXIF can carry GPS coordinates and adds weight to every copy.