BMP to Markdown Converter: Free, Private, No Upload
Convert BMP files to Markdown in your browser. Smaller output file, batch up to 20 files at once, no upload, no account, no watermark. Your files never leave your device.
- BMP to Markdown
- Batch up to 20 files
- No upload, no account
- Metadata stripped
- 1Add up to 20 images
- 2Pick from 18 formats
- 3Download or copy the code
Processed on your device. Your images are never uploaded, and metadata is stripped. How we keep it private
How do I convert BMP to Markdown for free?
Drop your BMP files into the tool above, choose Markdown as output, and download the result. Everything runs in your browser, so nothing is uploaded and there is no limit or watermark. It works on Windows, Mac, Linux, ChromeOS, iOS and Android — anywhere you have a modern browser.
- Price
- Free, no credits and no daily cap
- Account required
- No
- File uploaded to server
- No, processed locally in your browser
- Batch limit
- Up to 20 files at once
- Input format
- BMP
- Output format
- Markdown
- Best for
- Markdown workflows, smaller files, faster sharing
- Works on
- Chrome, Edge, Firefox, Safari, iOS and Android browsers
- Privacy
- No upload, no tracking, metadata stripped
- Output quality
- Adjustable 1-100, defaults to 90
How to convert BMP to Markdown
- 1
Drop your BMP files
Drag up to 20 BMP files onto the page or click to choose them. Everything runs in your browser.
- 2
Markdown is preselected
Output is already set to Markdown. Adjust quality, resize or batch if you want.
- 3
Download
Save each Markdown, or download all of them together as a ZIP.
BMP to Markdown: what changes and when it makes sense
BMP is a Bitmap image format. It is best known for a simple structure that legacy programs and embedded systems can read without a decoder library. The main drawbacks are enormous files and no reliable transparency.
Markdown is not an image format. It is a Markdown image reference that wraps the image data as text. Its main appeal is keeping a document and its image together in a single .md file. The main drawbacks are unreliable rendering across platforms and very long lines that make the file hard to edit.
BMP vs Markdown at a glance
| Property | BMP | Markdown |
|---|---|---|
| Type | Raster image | Text encoding of an image |
| Compression | Usually uncompressed (run-length encoding exists but is rare) | The image bytes are written out as Base64 text, which adds about 33 percent to the size |
| Transparency | None | Same as the embedded image |
| Animation | No | Same as the embedded image |
| Colour depth | 1 to 32 bits per pixel | Same as the embedded image |
| Support | Opens in browsers and most desktop software, but almost never used on the web | Depends on the Markdown renderer, because some block data URIs in images |
| History | Created by Microsoft for Windows 1.0 in 1985 as the native bitmap format for the Windows Graphics Device Interface. The "BM" signature has been unchanged since then. Still used in embedded systems and legacy Windows software. | Markdown image syntax  has been standard since 2004. Data URI support depends on the renderer — GitHub sanitises them, VS Code preview shows them, Obsidian shows them. |
What actually changes in this conversion
- Markdown is an encoding of the image data, not a new compression scheme. The text is about a third larger than the binary file, so what you gain is portability rather than a smaller size.
- Transparency follows the image data being encoded. Markdown itself is only a text wrapper.
- EXIF, GPS and camera data are stripped on every conversion. That is good for privacy, but you lose capture dates.
About BMP: history and technical details
Created by Microsoft for Windows 1.0 in 1985 as the native bitmap format for the Windows Graphics Device Interface. The "BM" signature has been unchanged since then. Still used in embedded systems and legacy Windows software.
Technical: File header 14 bytes (signature, size, reserved, offset) followed by DIB header (40+ bytes). Supports 1, 4, 8, 16, 24, 32-bit pixels. Rows padded to 4-byte boundaries. Pixels can be stored bottom-up or top-down. Optional RLE4/RLE8 rarely used.
Real-world size: A 12-megapixel photo is 36 MB as 24-bit BMP. As JPG it is 2-4 MB (90% smaller). A 1920x1080 screen at 32-bit BMP is 8.3 MB; as PNG 200-600 KB.
Popular tools: Windows Paint, IrfanView, XnView, ImageMagick, GIMP, Adobe Photoshop, embedded dev tools.
Alternatives: PNG (lossless, 5-20x smaller), TGA (game pipelines), TIFF (professional print), JPG (lossy, much smaller).
About Markdown: what you get
Markdown image syntax  has been standard since 2004. Data URI support depends on the renderer — GitHub sanitises them, VS Code preview shows them, Obsidian shows them.
Technical: . The line becomes extremely long and hard to edit. Some parsers cap line length or data URI size.
Real-world size: A 5 KB icon embedded in a README.md becomes a single ~7 KB line. GitHub renders it as broken. VS Code and Obsidian render it fine. Blog platforms vary.
Popular tools: VS Code, Obsidian, Typora, Marktext, GitHub (blocks), GitLab (blocks).
Alternatives: Relative path to image file, Hosted image URL, Markdown with reference links.
Browser and software compatibility
BMP: Opens in browsers and most desktop software, but almost never used on the web. Markdown: Depends on the Markdown renderer, because some block data URIs in images.
Markdown with an embedded image is not rendered everywhere. GitHub sanitises them.
Why people move away from BMP
- A 12 megapixel photo saved as 24-bit BMP is roughly 36 MB because pixels are stored almost raw.
- BMP has no practical support for transparency, and almost no web workflow expects it.
Why people choose Markdown
- Markdown with an embedded image keeps a document self-contained in a single .md file.
- It is useful for note-taking tools and offline documents where linked files tend to go missing.
Common mistakes with BMP
- Using BMP on web pages — files are 10-20x larger than PNG with zero benefit
- Expecting BMP transparency to work — most viewers ignore the alpha channel
- Converting large BMPs without checking disk space — can fill your drive
Best practices for keeping quality
- BMP is raw pixels, so the source has no compression damage. Convert at full size and choose the output quality freely.
- Some renderers, GitHub among them, do not display data URI images in Markdown. Check your target before relying on it.
- For documentation, a relative path to an image file is usually more portable and easier to maintain.
- Resize before converting if the image will be shown small. A 4000 pixel photo displayed at 800 pixels wastes bytes in any format.
- Check the result at 100 percent zoom, especially around text, edges and gradients, before you replace any originals.
- Keep your original files. Conversions to a lossy format cannot be undone.
- When you convert a set of images, use the same quality setting for the whole batch. The converter handles up to 20 files at once.
BMP to Markdown questions
Quick answers about privacy, quality, supported formats, file limits and how Markdown works.
Why convert BMP to Markdown?
Markdown files are typically smaller than BMP, which makes them faster to share, send and load. The trade-off is a small amount of image detail at low quality settings.
Will converting BMP to Markdown lose quality?
At 90% quality, most people cannot tell the difference. Use 85-95% for photos and you are fine.
Does Markdown keep transparency?
Markdown is only a text wrapper around the image data, so transparency depends on the image format inside it.
Are my files uploaded?
Never. Everything runs in your browser. Your files never leave your device. Open DevTools Network tab while processing — you will see no upload request.
Can I convert many files at once?
Yes, up to 20 files at once. Download them individually or all together as a ZIP.
Does the converter strip metadata?
Yes. Browsers do not pass EXIF data through a canvas, so GPS, camera model and dates are removed on every conversion. That is good for privacy.
Is it free?
Yes. No credits, no daily cap, no account, no watermark. The practical limit is your device memory.
Does GitHub support data URI images in Markdown?
No. GitHub strips data URIs for security. Use a relative image path or a hosted URL instead. GitLab has similar restrictions.
Your files never leave your device
No upload, no account, no tracking. Everything happens in your browser using the Canvas API and WebAssembly. You can confirm this in your browser's DevTools Network tab while the tool runs — no request carries your file. See why ToolDeck is different.