WebP to BMP Converter
Some older tools, embedded systems and classroom programs only read plain bitmap files. If you have a WebP and need a BMP, this converter decodes it on your device and writes an uncompressed 24-bit bitmap. You choose the background colour for any see-through areas, and the file is never uploaded.
How to convert WEBP to BMP
- Add your WEBP files by dropping them, clicking the drop zone or pasting.
- The output format is already set to BMP. Adjust quality or size if you need to.
- Press Convert and compare the original and new size for each file.
- Download each file or all of them as a ZIP.
When to convert, and when not to
- A legacy program, device or course exercise insists on BMP input.
- You need an uncompressed bitmap to process pixel by pixel in your own code.
- You want a simple format that has no compression step to go wrong.
- Do not use BMP for sharing or storing pictures online. The files are large, and WebP, JPG or PNG are far more practical.
What changes
- The output is a 24-bit BMP with no compression, so every pixel takes the same amount of space.
- BMP has no transparency here, so see-through areas are filled with your chosen background colour.
- The result is almost always much bigger than the WebP, and the size depends on the pixel dimensions rather than the content.
- Metadata is not carried over.
- An animated WebP is reduced to one still image.
Who still needs BMP files
BMP is one of the oldest image formats, and it survives because it is so simple. A bitmap file is essentially a small header followed by raw colour values. Programs that cannot afford a decompression library, hobby projects and some industrial equipment find that easy to read.
If a manual or tool asks for a BMP, it usually means exactly that: it wants raw pixels without any decoding step. A WebP cannot supply that, which is why converting is required.
You may also meet BMP in file-format lessons, where the point is to see exactly how an image is stored. Because the file holds a short header and then raw pixel rows, you can open it in a hex viewer and find the dimensions and colour values with a little reading. A WebP offers no such transparency about its contents.
Why the BMP is so large
Because nothing is compressed, a BMP stores every pixel at full size. A big photo that was small as a WebP can therefore become a very large bitmap. The file grows with the pixel dimensions, not with how complicated the picture is.
If size is a problem, use the Resize option to reduce the width and height before converting. Cutting the dimensions is the only way to make a BMP smaller, since there is no quality slider for an uncompressed format.
As a rough mental model, think of the BMP as a spreadsheet with one cell per pixel. Doubling both the width and the height quadruples the number of cells and therefore the file size. This is why a modest reduction in dimensions has such a large effect, and why Resize is the first thing to try when a bitmap is too big.
Background colour for transparent WebP files
The BMP written by this tool has no alpha channel. Any see-through part of your WebP is first painted with the background colour you choose, then your picture is drawn on top.
Pick a colour that suits where the bitmap will be used. White is the default. If the target program expects a particular key colour, such as pure green or black, set it here before converting.
If you are unsure which colour to choose, convert one file with the default white, open it, and check the edges of the picture. Light fringes around dark artwork mean you should pick a darker background. Because the colour is only used for areas that were see-through, opaque pictures are completely unaffected by this setting.
Privacy: your files stay on your device
- The tool decodes, resizes and encodes your pictures with your browser. The files are never sent to a server.
- To check it yourself: open the browser developer tools (F12), open the Network tab, convert a file, and look for any request that carries your image. You will see none.
Frequently asked questions
Is the BMP lossless?
The BMP stores the decoded pixels without further compression. It cannot restore detail that a lossy WebP already lost.
Why is the BMP so much bigger?
Bitmaps are uncompressed. Use Resize to lower the pixel dimensions if you need a smaller file.
What bit depth does the BMP use?
It is a 24-bit colour bitmap without transparency.
How is transparency handled?
Transparent areas are filled with the background colour you pick before the BMP is written.
Does anything get uploaded?
No. Conversion runs locally in your browser.