Convert PDF pages to 24-bit BMP bitmaps
The PDF to BMP converter turns each page of a PDF into a Windows bitmap (.bmp) file: plain, uncompressed, 24 bits per pixel. Choose a resolution, select the pages you need and download each bitmap or a ZIP of all of them.
BMP is rarely the best format for sharing, but it is often the required one. Older Windows programs, label and badge printers, industrial and machine-control software, microcontroller and e-paper display projects, some LED sign editors and classroom software only accept bitmaps, because a BMP can be read with a few lines of code and no decompression library.
The pages are rendered by pdf.js and written by a small BMP encoder, both running in your browser. Nothing is uploaded, so the tool is safe for internal documents and drawings.
How to convert a PDF to BMP
- Drop a PDF onto the box above or click it to choose a file.
- Pick a resolution. The hint underneath shows the pixel size and the approximate file size of page 1, so check it before choosing 300 DPI.
- Enter the pages you need, such as
1or3-5, or leave the box empty for all pages. - Press “Convert to BMP”.
- Download individual bitmaps, or press “Download all (ZIP)” — the ZIP is compressed, so it is much smaller than the bitmaps themselves.
PDF to BMP features
Standard 24-bit BMP
A 54-byte header (BITMAPFILEHEADER + BITMAPINFOHEADER) followed by uncompressed BGR pixels — the variant virtually every program and library can read.
Size preview
Before converting you see the pixel dimensions and the expected size of each bitmap, so there are no surprises.
Correct physical size
The chosen DPI is stored in the file as pixels per metre, so Windows and print software know how large the page is.
Exact pixel sizes
Pages render at the exact DPI you choose — useful when a device needs, say, a 96 DPI image to fit its screen.
Compressed ZIP download
Bitmaps compress very well, so downloading many pages as a ZIP saves a lot of time and space.
Why BMP files are so large
A 24-bit BMP stores three bytes (blue, green, red) for every pixel with no compression, and pads each row to a multiple of four bytes. The file size is therefore 54 + rowBytes × height, where rowBytes is width × 3 rounded up to a multiple of 4. Here is what that means for one A4 page:
| Resolution | Pixels (A4) | BMP size per page | Ten pages |
|---|---|---|---|
| 72 DPI | 595 × 841 | about 1.4 MB | about 14 MB |
| 96 DPI | 793 × 1122 | about 2.5 MB | about 25 MB |
| 150 DPI | 1240 × 1753 | about 6.2 MB | about 62 MB |
| 300 DPI | 2480 × 3507 | about 24.9 MB | about 249 MB |
BMP compared with PNG
The size of a BMP depends only on its pixel count, never on what the page shows: a blank page and a dense photo page at the same DPI produce exactly the same file size. PNG stores the same pixels losslessly but compresses them, so a mostly white text page usually becomes many times smaller. That is why a ZIP of bitmaps downloads so much faster than the bitmaps themselves.
When to choose BMP — and when not to
- Choose BMP when a program, device or assignment explicitly asks for .bmp, or when you are loading images into firmware or a microcontroller that has no PNG or JPEG decoder.
- Don’t choose BMP for email, websites or chat. Use PDF to PNG for lossless pages at a fraction of the size, or PDF to JPG for the smallest files.
- Need an exact pixel size, such as 800 × 480 for a display panel? Convert at a DPI close to it, then fine-tune with the Image Resizer.
- For a single-colour (1-bit) or 256-colour bitmap, convert here and reduce the colours in an image editor; this tool always writes full 24-bit colour.
Technical details
Rows are stored bottom-up (a positive height in the header), which is the most widely supported layout. Pages are rendered on a white background because 24-bit BMP has no alpha channel. Very large pages are capped at about 16 megapixels to stay within browser memory, and the real DPI is shown under each image when that happens.
PDF to BMP FAQ
How do I convert a PDF to BMP?
Open the PDF above, choose a resolution and press “Convert to BMP”. Each selected page becomes a 24-bit .bmp file that you can download on its own or in a ZIP.
Is a BMP better quality than a PNG?
No — both are lossless, so the pixels are identical. BMP simply skips compression, which makes it larger but easier for simple software to read.
Why is my BMP file so big?
Bitmaps are uncompressed: an A4 page at 300 DPI is about 25 MB. Choose 96 or 150 DPI if the receiving program allows it, and download several pages as a ZIP.
Can I make a 1-bit or 8-bit bitmap?
Not directly. The converter writes 24-bit colour, which every BMP reader supports. Use an image editor afterwards if a device needs fewer colours.
Does it work on a phone?
Yes, in any modern mobile browser. Keep to 150 DPI or lower on phones, because large bitmaps take a lot of memory.
Is my PDF uploaded?
No. The PDF is rendered and encoded inside your browser, and no copy is sent to a server.