How to convert BMP to ICO
- Click Choose files or drop your BMP images into the box above — up to 10 at a time on the free plan.
- Optionally choose which icon sizes to include, from 16×16 up to 256×256 pixels.
- Conversion starts right away. Download each ICO file, or click Download all to get them as one ZIP.
BMP vs ICO
| BMP | ICO | |
|---|---|---|
| Compression | Uncompressed | Lossless |
| Transparency | No | Yes |
| Animation | No | No |
| Colors | Usually 24-bit color, stored uncompressed | Several sizes (16×16 to 256×256) in one file, full alpha |
| File size (photos) | Very large | Small |
| Opens on | Windows and most image viewers; rarely accepted on the web | Windows, every browser (as a favicon) |
| Best for | Old Windows software, embedded devices and tools that need raw pixels | Website favicons and Windows application or shortcut icons |
About BMP and ICO
What is BMP?
BMP is an old Windows format that usually stores every pixel uncompressed. A photo saved as BMP can be 10–20 times larger than the same JPG. Today it is mostly needed for legacy software, some printers, industrial machines and microcontroller displays.
- Simple, uncompressed and lossless
- Readable by old and embedded software
- Enormous files
- No useful transparency or metadata
- Not accepted by most websites
What is ICO?
An ICO file bundles several square versions of the same icon — typically 16×16, 32×32 and 48×48 pixels, up to 256×256 — so Windows and browsers can pick the sharpest one for each place it is shown. It is still the most compatible format for a website favicon.
- Several sizes in one file
- Works as a favicon in every browser
- Transparency
- Only square images up to 256×256
- Not useful outside icons
Why GlideConvert?
- Private by design. Your files are converted on your own device by your browser — they are never uploaded to a server. That keeps them private, avoids upload waits and means there is no queue.
- Fast. Images convert in a fraction of a second; video uses your device’s hardware encoder.
- Free. No sign-up, no watermark. 10 images, 5 audio files or one video at a time — Pro lifts the limits and removes ads.
Frequently asked questions
Will converting BMP to ICO reduce quality?
No. ICO is lossless, so the result looks exactly like your BMP.
Which sizes should a favicon ICO contain?
A website favicon usually contains 16×16, 32×32 and 48×48 pixel images; Windows app and shortcut icons also use 256×256. All of these are selected by default. For a complete favicon set (PNG, Apple touch icon and manifest) use the Favicon generator.
Can I convert several BMP images at once?
Yes. The free plan handles 10 images at a time, and you can download everything as a single ZIP. Pro removes the batch limit, converts files in parallel and supports files up to 4 GB.
Are my files uploaded to a server?
No. GlideConvert runs entirely in your browser: images are processed with the browser’s built-in codecs and WebAssembly, video and audio with hardware-accelerated WebCodecs (or a WebAssembly build of FFmpeg for older formats). Nothing is sent anywhere — you can even disconnect from the internet once the page has loaded.
Does it work on iPhone, Android, Mac and Windows?
Yes. It works in any up-to-date browser — Chrome, Edge, Safari, Firefox or Samsung Internet — on phones, tablets and computers, with nothing to install. On phones, extremely large images may be scaled down to fit within the browser’s memory limit; you will see a note if that happens.