BMP to Data URL Converter: Free, Private, No Upload

Convert BMP files to Data URL 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 Data URL
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 Data URL for free?

Drop your BMP files into the tool above, choose Data URL 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: Data URL
Best for: Data URL 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 Data URL

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
Data URL is preselected
Output is already set to Data URL. Adjust quality, resize or batch if you want.
3
Download
Save each Data URL, or download all of them together as a ZIP.

BMP to Data URL: 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.

Data URL is not an image format. It is a Data URL (the data: URI scheme) that wraps the image data as text. Its main appeal is embedding small images directly in HTML, CSS or JSON with no extra network request. The main drawbacks are a size about a third larger than the original, no separate caching and awkward editing.

BMP vs Data URL at a glance

Property	BMP	Data URL
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	Works in all modern browsers, though very long strings can hit limits in some older browsers and email clients
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.	The data: URI scheme was standardised in RFC 2397 in 1998 by Larry Masinter at Xerox PARC. It became widely used in the 2010s for embedding small icons and CSS backgrounds without extra HTTP requests.

What actually changes in this conversion

Data URL 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. Data URL 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 Data URL: what you get

The data: URI scheme was standardised in RFC 2397 in 1998 by Larry Masinter at Xerox PARC. It became widely used in the 2010s for embedding small icons and CSS backgrounds without extra HTTP requests.

Technical: Format: data:[<mediatype>][;base64],<data>. For images: data:image/png;base64,iVBORw0KGgo... The base64 encoding expands data by ~33%. Browsers typically cap data URLs at 2 MB (Chrome, Firefox); Safari has higher limits.

Real-world size: A 5 KB PNG becomes ~7 KB as base64 data URL. A 50 KB image becomes 67 KB. Best practice is to use data URLs only for images under 10 KB where the extra request overhead would dominate.

Popular tools: Webpack (asset/inline), Vite (assetsInlineLimit), Next.js (dangerouslyAllowSVG), online base64 converters.

Alternatives: External image file (cacheable), SVG inline (vector), HTTP/2 push (deprecated), font-based icons.

Browser and software compatibility

BMP: Opens in browsers and most desktop software, but almost never used on the web. Data URL: Works in all modern browsers, though very long strings can hit limits in some older browsers and email clients.

Data URLs work in all modern browsers. Very long strings can hit length limits.

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 Data URL

A data URL puts an image straight into HTML, CSS or JavaScript, removing a network request.
It is handy in single-file HTML pages, email templates, test fixtures and demos that cannot rely on external files.
Tiny icons and low-quality placeholders are the best fit.

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.
Keep encoded images small, ideally a few KB. Base64 adds about a third to the size, and the browser cannot cache an inline image separately.
Compress or resize the image first, then encode it.
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 Data URL questions

Quick answers about privacy, quality, supported formats, file limits and how Data URL works.

Why convert BMP to Data URL?

Data URL 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 Data URL lose quality?

At 90% quality, most people cannot tell the difference. Use 85-95% for photos and you are fine.

Does Data URL keep transparency?

Data URL 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.

When should I use data URLs?

For small images (under 10 KB) in single-file HTML, email templates, or CSS where an extra HTTP request would cost more than the encoding overhead. Never for photos or large icons.

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.