# BMP to PDF Converter > A free online tool that puts BMP images in one PDF, one image on each page, in the order you set, after saving each one as a PNG or JPG in your browser. Use this free BMP to PDF converter to turn BMP images, such as old scans and screen captures, into one PDF file. Each image becomes one page. Your browser opens each BMP and saves it as a PNG, then you choose the page order and page size, and download the result. No signup is needed for a basic conversion. ## Key facts - Input: BMP, JPG or PNG files, up to 20 without an account (100 signed in), each up to 5 MB (10 MB signed in) after the browser has saved it again; a converted PNG can have up to 16 megapixels, a converted JPG up to 50 megapixels. - Conversion: your browser opens each BMP and saves it as a PNG before the upload, so no pixel is changed; a BMP your browser cannot open is refused before anything is sent. - Settings: page order, page size (fit each image, A4 or Letter), orientation (A4 and Letter) and margin (none, 0.25, 0.5 or 1 inch). - The PDF has no password. Without an account each image is uploaded with its own human check. - API: the image_to_pdf operation reads JPG, PNG and TIFF only, so convert a BMP first; then POST each image to https://api.aiipworld.com/v1/uploads, POST https://api.aiipworld.com/v1/pdf-jobs with the upload ids in page order, and poll GET /v1/jobs/:id. - Free without an account: up to 20 PDF jobs and 40 image uploads per day per visitor (each image counts as one upload), no watermark. Signed in, each job costs 1 credit, plus 1 credit for each started 20 images beyond the first 20 and for each started 20 MB of result beyond the first 20 MB (100 free credits every month). - Files are deleted automatically: 10 minutes after conversion without an account, 1 day with a free account. ## Sources - [PDF Association: ISO 32000-2 (PDF 2.0)](https://pdfa.org/resource/iso-32000-2/) - [Library of Congress: BMP, Microsoft Windows Bitmap (format description)](https://www.loc.gov/preservation/digital/formats/fdd/fdd000189.shtml) Last reviewed: 2026-10-18 ## How it works 1. Add your BMP files. You can also add JPG and PNG files. 2. Each BMP is opened and saved again as a PNG or JPG in your browser. Nothing is sent until you start the conversion. 3. Put the files in the order you want the pages to appear. 4. Choose a page size: Fit each image, A4 or Letter. 5. Choose the orientation and margin. 6. Select "Convert to PDF" and download the file, named images.pdf. ## How to convert BMP to PDF Start by adding your BMP files to the tool. The tool checks each file by reading its first bytes, so the file must really be a BMP (or a JPG or PNG) and not just named like one. Set the page order, page size and margin, then select "Convert to PDF". When the job ends, the result panel shows a download link for images.pdf. The steps are the same for one file or many. Each image becomes one page of the PDF, in the order you set. ## What happens to your BMP first The PDF converter reads JPG, PNG and TIFF files. A BMP is a different format, so the page opens it with your browser's own BMP decoder and saves the picture again as a PNG before it is sent. A PNG keeps every pixel of the BMP, so nothing is lost in this step: - A BMP is saved as a PNG, never as a JPG, because many BMP files are screen captures, drawings and scans with sharp edges, where a JPG would add blur. - A BMP with transparent pixels (a 32-bit BMP) keeps them in the PNG. The PDF engine puts them on the white page, so transparent areas show as white. - A BMP that your browser cannot open is refused with a message, and nothing is sent. ## Put several BMP files in one PDF To put several BMP files in one PDF, add all of them before you convert. Each image becomes one page, in the order you set. You can mix BMP, JPG and PNG files in one job. Without an account, the images together can be up to 20 MB. Signed-in users can add up to 100 images per PDF, with the total up to 100 MB. - Without an account, the limit is 20 images per PDF. ## Choose the page size You can choose Fit each image, A4 or Letter as the page size. Fit each image makes each page the size of its picture, using 96 pixels per inch. A4 and Letter give every page the same fixed size, and the picture is fitted to the page. With A4 or Letter a small picture can be enlarged to fit the page, and the result panel reports it. Choose Fit each image to keep each page the size of its picture. ## Margins and orientation You can set a margin for the pages (none, 0.25, 0.5 or 1 inch), and the orientation for A4 and Letter pages. The margin works with every page size. With Fit each image, the page grows by the margin on each side. Choose None for no margin, so the image can use the whole page; on A4 or Letter it keeps its proportions and is centred. ## Is the BMP quality kept The pixels of the BMP are kept. The BMP is saved as a PNG, which is lossless, and the PNG is packed into the PDF without changing its pixels. Check the first page of your PDF before you share it. Results vary with the file. ## File size of the PDF A BMP stores a picture with little or no compression, so a BMP file is often much bigger than the PDF made from it. The PNG inside the PDF is compressed without losing pixels. A photo saved as a BMP gives a big PNG, which is why the limits below apply to the converted picture. Results vary with the file. ## Limits: images, size and pixels The converted picture goes through the same limits as the PNG to PDF and JPG to PDF pages. A converted PNG can be up to 16,777,216 pixels (16 MP). All PNG files in one job together can be up to 32 MP without an account and 64 MP signed in. A converted JPG can be up to 50 MP and does not count toward that total. Without an account, each image can be up to 5 MB. Signed-in users can use up to 10 MB per image. The limit applies to the picture after it has been saved again in your browser, which can be larger than the BMP file. If a picture is too big, the page tells you before anything is sent. In that case make the BMP smaller first, for example with the resize tool on this site. ## Convert BMP to PDF from code The PDF API reads JPG, PNG and TIFF files for the image_to_pdf operation. The BMP step happens in this web page, so from code you convert the file first, for example with the image convert operation (see /docs/), and then upload the JPG or PNG. Upload each file with a POST to https://api.aiipworld.com/v1/uploads. Send the raw bytes with Content-Type image/png or image/jpeg, one file per request. The answer contains an upload_id. Then POST to https://api.aiipworld.com/v1/pdf-jobs with JSON that has op, params and files, where files lists your upload_id values. Poll GET /v1/jobs/:id until the job succeeds, fails or times out. The download_url is a short-lived signed link. The page shows a ready cURL, Node and Python example below the tool, built from the settings you choose. Possible errors include 413 file_too_large, 422 unsupported_image, 402 insufficient_credits and 429 rate limited. ## Privacy: what happens to your files The BMP is opened in your browser. The PNG or JPG made from it is then sent to our server, and the PDF is made there. You must have the right to use what you upload, as set out in the Acceptable Use Policy. The uploaded file is used only to make the result. The working copy of the upload is deleted as soon as the job ends, whether it succeeds or fails. The result is deleted after 10 minutes in the free web tool. Download links are short-lived. We keep only basic job details such as the operation, time and status, not your file contents, and signed-in users can see their jobs in the dashboard. Anonymous use needs a human check by Cloudflare Turnstile. ## Questions ### Can I convert BMP to PDF for free? Yes, you can convert BMP to PDF for free on this page. Anonymous use needs a human check for each uploaded image, and it is limited to 20 PDF jobs and 40 image uploads per day per visitor. ### How do I put several BMP files in one PDF? Add all the BMP files before you select "Convert to PDF". Each image becomes one page in the order you set. ### Why is the BMP converted in my browser first? The PDF converter reads JPG, PNG and TIFF only. Your browser opens the BMP and saves it as a PNG first, so the BMP is not sent as it is. ### Does converting BMP to PDF reduce the quality? No. The BMP is saved as a PNG, which keeps every pixel, and the PNG is packed into the PDF without changing its pixels. Results vary with the file. ### Why is my PDF smaller than the BMP? A BMP is stored with little or no compression. The PNG inside the PDF is compressed without losing pixels, so the PDF is often much smaller. ### What happens to transparent areas? If your BMP has transparent pixels, they stay in the PNG, and the PDF puts the picture on the white page, so those areas show as white. ### How do I change the order of the pages? Set the page order in the tool before you convert. The pages follow the order you choose. ### How many files can I add? Without an account you can add 20 images per PDF. Signed-in users can add 100 images per PDF. ### Does the PDF have a password? No. The tool does not add a password to the PDF. ### Can I convert BMP to PDF in my own code? Yes, with two steps. The PDF API reads JPG, PNG and TIFF, so convert the BMP first and then upload the result. See /docs/ for the general API. ## Related - [WebP to PDF Converter](https://aiipworld.com/tools/webp-to-pdf/index.md) - [GIF to PDF Converter](https://aiipworld.com/tools/gif-to-pdf/index.md) - [JPG to PDF](https://aiipworld.com/tools/jpg-to-pdf/index.md) - [PNG to PDF Converter](https://aiipworld.com/tools/png-to-pdf/index.md) - [TIFF to PDF: Convert Multi-Page TIFF Files Online](https://aiipworld.com/tools/tiff-to-pdf/index.md) Page: https://aiipworld.com/tools/bmp-to-pdf/