Secure server conversion
BMP to WebP Converter
Convert a Windows BMP into WebP, free and without an account. Bitmaps store every pixel uncompressed, so the savings are large: about 89% smaller for a photograph and over 99% for a simple graphic in testing. It is the quickest way to make old bitmaps usable on a website.
Drag and drop your BMP images here
Add several at once. Each file is processed and then deleted from our server.
Up to 20 MB per file Batch ready
Higher keeps more detail; lower makes a smaller file. Applies to images you add after changing it.
Conversion queue
→
Your browser could not read this file, so it was converted on our server and deleted there straight away.
Your file had frames or pages. Only the first is in this download.
Step by step
How to convert BMP to WEBP in 3 steps
-
Add your BMP files — several at once is fine
-
Adjust quality if you like; 85 suits most images
-
Download your WebP files — each one as soon as it is ready
Format comparison
BMP vs WEBP
BMP (Windows Bitmap)
UncompressedAn early Windows format that stores pixels more or less raw, with little or no compression.
- Read by old and embedded software that knows nothing newer
- No compression artefacts
- Very large files for the image size
WebP
Lossy or losslessA web format from Google that can work like JPG or like PNG, usually producing a smaller file than either.
- Smaller files than JPG or PNG for most images
- Supported by every current browser
- Some older desktop software and upload forms still reject it
From raw pixels to web compression
A BMP records three bytes for every pixel with no compression, so a 1920 × 1080 bitmap is about 6.2 MB regardless of what it shows. WebP was designed for the web: it compresses images heavily while keeping them looking right.
Measured at this page's default quality:
- A photograph: 360 KB → about 39 KB, 89% smaller.
- A simple graphic: 720 KB → about 3 KB, over 99% smaller.
These were measured with the same encoder that converts your files.
Lossy, at a sensible setting
This conversion uses WebP's lossy mode, which discards detail the eye is unlikely to notice. At 85 a photograph looks essentially unchanged. For images that must stay pixel-exact — screenshots with fine text, pixel art, diagrams — BMP to PNG is lossless and still far smaller than the bitmap.
Quality
Quality and file size
- 85, the default — photographs look essentially unchanged.
- 90–100 — for detailed images and screenshots, where fine edges matter.
- 60–75 — for thumbnails and backgrounds where size matters most.
Screenshots and text
Old BMPs are often screenshots. Lossy compression can soften small text and single-pixel lines slightly; raising the quality reduces that. If text must be perfectly crisp, PNG keeps every pixel exact.
Large batches
Each bitmap is uploaded to our server and converted in turn. Bitmaps are large, so a big batch takes a while to upload; smaller groups show results sooner.
Converting a whole folder
You can drop many bitmaps at once. Each is converted in turn, and each one can be downloaded as soon as it is ready.
The savings add up quickly on large images. Measured on a 3000 × 2000 photograph — one previously saved as a JPEG, which makes it compress more easily than a camera original: 18 MB as a BMP, and 102 KB as a WebP at this page's default quality — under 1% of the original.
Bitmaps over the upload limit
A BMP's size is fixed by its dimensions, not by what it shows: width × height × 3 bytes. One the size of a 12-megapixel camera photo, 4000 × 3000, is about 36 MB. Each file can be up to the size shown on the upload area, so the very largest bitmaps may not fit.
There are two ways round it, both in Paint, which comes with Windows. For a screenshot or graphic, choose Save as → PNG picture: PNG is lossless and shrinks flat colour dramatically, so nothing is lost, and you can then convert it with PNG to WebP. For a photograph, choose Resize and set 50 percent before saving: half the width and height is a quarter of the bytes, and still more than most web pages ever display. Either way, the WebP you end up with is far smaller than the bitmap you started from.
BMP resolution and colour depth
WebP does not store a DPI setting, so a bitmap's resolution value is not carried across — it has no effect on how the image looks on screen. Low colour depth bitmaps, such as 256-colour images, convert to full-colour WebP with the same appearance.
When BMP to WebP makes sense
- Publishing old images on a website, where bitmaps are far too large.
- Sharing screenshots and scans that are awkwardly large as BMP.
- Modernising legacy application graphics for a web or mobile version.
WebP, AVIF or PNG?
- WebP — small, quick to create, and very widely supported.
- AVIF — smaller still for most images, but slower to create and supported by less software outside browsers.
- PNG — lossless and universal; larger than WebP.
Going the other way
WebP to BMP reverses this, for legacy software that only reads bitmaps.
Privacy
What happens to your file
This tool runs on our server, so it works the same on every phone and computer. Your file is uploaded, and this is exactly what happens to it:
- Stored outside the public web root under a random name, never under your file's name.
- Processed, with the original upload deleted immediately — whether it succeeded or failed.
- The result sits behind a signed link that only you receive, which stops working after 20 minutes, and the file is deleted the moment you download it.
- Anything never collected is deleted automatically within 30 minutes.
- The image itself is never logged or kept. If a conversion fails, we record the formats involved and the error — not the file.
- Camera metadata, including any GPS coordinates recording where a photo was taken, is removed from the result. Only the rotation needed to show the image the right way up is kept.
Questions & answers
BMP to WebP: frequently asked questions
Is my image uploaded?
Yes. The conversion runs on our server so that it works the same on every device. Your upload is deleted the moment the WebP is made, the WebP is deleted as soon as you download it, and no one looks at your images.
How much smaller will the WebP be?
Much smaller. At the default setting a photograph went from 360 KB to about 39 KB and a simple graphic from 720 KB to about 3 KB.
Does it lose quality?
A little: this uses WebP's lossy mode, and at the default photographs look essentially unchanged. For pixel-exact screenshots, pixel art or diagrams, convert to PNG instead.
Is the DPI kept?
No — WebP does not store a DPI setting. It makes no difference to how the image looks on screen.
Should I use WebP or AVIF?
WebP is more widely supported and quicker to create. AVIF is usually smaller still, but slower to create and less supported outside browsers.
Keep going
Related image tools
BMP to AVIF Converter
Convert BMP to AVIF, the most efficient web image format. A photo shrank 89% and a simple graphic 99.9% in testing. When to choose WebP or PNG instead.
BMP to PNG Converter
Convert BMP to PNG with no quality loss at all. Typically 70-90% smaller, and perfect for screenshots and pixel art.
BMP to JPG Converter
Convert BMP images to JPG. BMP stores images uncompressed, so the saving is usually enormous — often 95% or more.
WebP to BMP Converter
Convert WebP to BMP for software that cannot open WebP. Expect a much larger file — about ten times for a photo — and see what happens to transparency.