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BMP to ICO Converter

Turn BMP files into ICO in a couple of clicks. BMP is an uncompressed raster bitmap; ICO is a multi-resolution icon container for favicons and apps. The conversion is lossless — every pixel, sample or byte in the source is preserved.

Not uploaded to any serverConverted on this deviceGone when you close the tabHow this works

Drop your files here

BMP files (.bmp, .dib) · up to 120 MB each

or paste files from your clipboard

Ready when you are

Drop a BMP file above and FileTools360 will turn it into ICO — right here on your device, without uploading anything.

⌘K to search converters

How to use it

  1. 1

    Add your BMP files

    Drag them onto the drop area, choose them from your device, or paste them from your clipboard. You can queue several at once. Nothing is sent anywhere — the file stays on this device.

  2. 2

    Adjust the settings if you want to

    The defaults suit most people. Open Advanced to control metadata removal.

  3. 3

    Convert and download

    Press Convert. Everything happens on your own device — nothing is uploaded. Download files one by one, or grab them all as a ZIP.

Privacy, in plain words

Is it safe? Your BMP file is not uploaded anywhere

What “uploaded” normally means. On most online converters, pressing the button copies your file across the internet onto a computer owned by that website. That copy is what the word “upload” means, and it is the part nobody explains.

What happens instead. This site does not do it. There is no server here that receives files, so your BMP file is read, converted and handed back by the browser you are using right now. It never travels — so there is no copy to store, read, leak or hand over.

Check it yourself in ten seconds

Turn off your Wi-Fi after this page has loaded, then convert a file anyway. It still works, because everything needed is already on your device.

The longer explanation of how this works, and the full detail of what is and is not stored on the privacy page.

Why this matters more than it sounds

Photographs carry more than what is in the frame — most also carry the time, the device and often the GPS coordinates where they were taken. It matters more than it sounds, because of what images usually are:

Medical scans and photographs

X-rays, results, images of a condition

Photographs of children

family pictures that should stay in the family

Passport and visa photos

biometric-grade images of your face

Screenshots of private messages

conversations that included other people

A file that is never sent cannot be kept, leaked, subpoenaed or used to train anything. That is a property of how this works, not a promise about how carefully it is run.

BMP and ICO explained

BMP stores pixels essentially raw, with little or no compression. A 1920×1080 BMP is around 6 MB regardless of what the picture contains, because every pixel takes the same space whether it is part of a gradient or a flat colour.

ICO is a container that holds several versions of the same icon at different sizes, so the operating system or browser can pick the one that fits. It is capped at 256×256 pixels.

Where BMP files come from
Legacy Windows software, some scientific and industrial imaging tools.
Where ICO is used
Website favicons and Windows application icons.

BMP vs ICO

The two formats solve different problems, which is why converting between them involves trade-offs rather than a straight upgrade.

BMP compared with ICO
PropertySourceTarget
CompressionUncompressedLossy or lossless
TransparencyNoYes
AnimationNoNo
Introduced19901985
Browser supportBroad, though rarely the best choice today.Browsers and Windows. Sizes are capped at 256×256.
BMP is stronger at
Trivially simple to read and write. No compression artefacts whatsoever. Still readable by very old software.
ICO is stronger at
Holds multiple resolutions in one file. The format browsers expect for favicon.ico. Supports transparency.

Why convert BMP to ICO?

People make this switch when they run into the limits of BMP: almost always — PNG gives you the same lossless fidelity in a fraction of the space. ICO is the better fit when you are making a favicon or a Windows application icon.

There is also a size argument: BMP stores data with little or no compression, so the ICO version is normally dramatically smaller for the same content.

BMP limitations that prompt the switch
Enormous files. No standard support for transparency in most variants. Effectively unusable on the web.
What you give up
Capped at 256×256. Not a general-purpose image format.

Does converting BMP to ICO reduce quality?

Both formats store the content without discarding data, so this conversion preserves it exactly. The file size may change because the two formats compress differently, but the content itself is unaffected.

About these formats

Source

Windows Bitmap

Uncompressed raster bitmap. Large but simple.

Extensions
.bmp, .dib
MIME type
image/bmp
Best for
Legacy Windows software · Raw pixel exchange
Compatibility
Broad, though rarely the best choice today.

Target

Windows Icon

Multi-resolution icon container for favicons and apps.

Extensions
.ico
MIME type
image/x-icon
Best for
Favicons · Windows application icons
Compatibility
Browsers and Windows. Sizes are capped at 256×256.

Icons are capped at 256×256 by the ICO format itself. Larger sources are downscaled.

Good to know

BMP to ICO Converter — questions

How do I convert BMP to ICO?

Drop your BMP file onto the area above, then press Convert. The ICO file saves straight to your device. You do not need an account, and there is no watermark.

Is it safe to convert BMP files here — are they uploaded to a server?

No, nothing is uploaded. On most online converters, pressing the button copies your file across the internet onto a computer owned by that website; it is converted there and sent back. That copy is what "upload" means, and it is the part that puts your file out of your control. This site does not do it. Your BMP file is read and converted by the browser you are using right now and never leaves this device, so there is no copy for anyone to store, read or hand over. You can prove it: turn off your Wi-Fi after this page loads and the conversion still works.

Can I convert confidential BMP files, like bank statements or contracts?

Yes, and that is the case this site was built for. Because the file never leaves your device, a confidential document is no more exposed than it is sitting in your own folder — there is no transfer, no copy on someone else's hardware, no retention period to read about and no staff with access. Nothing is logged about the file either: not its name, not its size, not its contents. The one thing worth saying plainly is that this protects the file in transit and at rest on our side, not from anything already on your own computer.

What should I know before converting BMP to ICO?

Icons are capped at 256×256 by the ICO format itself. Larger sources are downscaled.

Does converting to ICO reduce quality?

No. ICO is a lossless format, so the conversion preserves exactly what is in your BMP file. Note that it cannot recover detail that was already discarded when the BMP was first created — a lossless container does not undo earlier compression.

How large a file can I convert?

Up to 120 MB per file for this conversion. Because the work happens in your browser, the practical limit is your device's memory — larger files work on a desktop with plenty of RAM and may fail on an older phone.

Can I convert several files at once?

Yes. Add as many as you like and press Convert All. Each file is processed independently, so one failure does not stop the rest, and you can download everything together as a ZIP.

Can I use this on my phone?

Yes. FileTools360 works in mobile browsers on iOS and Android, including choosing files straight from your camera roll. Very large images may run out of memory on a phone — those are better converted on a laptop.

Related converters

All image converters
ICO → BMP
BMP → AVIF
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BMP → JPG
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BMP → PNG
BMP → SVG
BMP → TIFF

Runs entirely in your browser

FileTools360 by the numbers

527 converters and tools65 file formatsnothing ever uploaded.