Does converting BMP to ICO improve the image quality?

No. BMP and ICO both store every pixel exactly, so the picture is untouched — only the file format changes.

What happens to transparency?

There is nothing to preserve: BMP has no transparency, so this does not come up.

Is there a file size limit?

No limit that we impose. The only ceiling is your device's memory, so a very large photo or a long recording may take a few seconds.

Are my files uploaded anywhere?

No. The conversion runs inside this browser tab, so the file never leaves your device — go offline once the page has loaded and keep converting.

BMP to ICO converter

Convert BMP files to ICO right in your browser. Nothing is uploaded, there is no sign-up, and there is no file limit.

Runs on your device
No upload, no queue
Batch + ZIP download

Drop files here, or click to choose

Supports PNG, JPG, WEBP, AVIF, BMP, GIF, SVG, HEIC, TIFF and ICO — and writes GIF, TIFF and PDF too. Files stay on your device.

Convert to

Max width (px, optional)

Quality

How to convert BMP to ICO

Drop your BMP file onto the box above, or click it to browse.
Choose ICO as the output format.
Press convert, then download the result.

BMP vs ICO

BMP works well for uncompressed editing work. ICO works well for favicons and app icons. The table below compares the two on the things that usually decide the choice.

	BMP	ICO
Compression	Lossless	Lossless
Transparency	No	Yes
Best for	uncompressed editing work	favicons and app icons

Questions about BMP to ICO

Does converting BMP to ICO improve the image quality?: No. BMP and ICO both store every pixel exactly, so the picture is untouched — only the file format changes.
What happens to transparency?: There is nothing to preserve: BMP has no transparency, so this does not come up.
Is there a file size limit?: No limit that we impose. The only ceiling is your device's memory, so a very large photo or a long recording may take a few seconds.
Are my files uploaded anywhere?: No. The conversion runs inside this browser tab, so the file never leaves your device — go offline once the page has loaded and keep converting.

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