JPG (Joint Photographic Experts Group (JPEG)) and ICO (Windows Icon) are built for different jobs. JPG is typically used for photos, social media, email attachments, while ICO is best for favicons, windows app icons. Converting lets you open, share or upload your files wherever ICO is expected.
How to use the JPG to ICO converter
- Add your JPG filesClick “Choose Files” or drag and drop them into the box. You can add many files at once — or paste a file with Ctrl+V.
- Choose ICO and adjust settingsICO is selected automatically. Optionally open Settings to change quality, size or background.
- Convert and downloadPress “Convert”. Your ICO files appear instantly — download them one by one or all together as a ZIP.
JPG vs ICO
JPG Joint Photographic Experts Group (JPEG)
JPG is the most widely supported photo format. It uses lossy compression that discards detail the eye barely notices, producing small files that open on every device, browser and app — ideal for photographs, less so for text or line art.
- Compression
- Lossy
- Features
- No transparency
- Origin
- 1992, JPEG committee
- Best for
- Photos, social media, email attachments
ICO Windows Icon
ICO is the icon container used by Windows and by websites for favicons. A single ICO file can hold several sizes (16×16 up to 256×256) so the system picks the sharpest one for each place it is displayed.
- Compression
- Lossless (PNG inside)
- Features
- Supports transparency
- Origin
- 1985, Microsoft
- Best for
- Favicons, Windows app icons
Why use ConvertMathly?
Files are processed on your device and never uploaded. Close the tab and they are gone.
No account, no daily cap, no queue and no watermark — convert as much as you want.
No waiting for uploads or downloads: results are ready as fast as your device can process them.
Windows, Mac, Linux, Chromebook, iPhone and Android — any modern browser, nothing to install.
Frequently asked questions
How do I convert JPG to ICO?
Add your JPG files above, make sure ICO is selected and press Convert. The ICO files are ready to download a few seconds later — no installation or account required.
Is ICO lossless?
ICO is lossless (png inside), so your image keeps its detail.
Is there a file size or daily limit?
No. Since everything runs locally, there are no daily caps, queues or file size limits beyond what your device can handle.
Are my JPG files uploaded to a server?
No. ConvertMathly converts files entirely inside your web browser using JavaScript and WebAssembly. Your files never leave your computer or phone, which makes it safe for private photos and documents.
Can I convert multiple JPG files at once?
Yes — add as many files as you like. They are converted one after another and you can download everything in a single ZIP.