Convert BMP to PNG Online Free

Convert uncompressed BMP bitmaps to PNG format. Get dramatically smaller files with lossless compression - every pixel is preserved exactly while file size drops by 50-80%.

By ChangeThisFile Team · Last updated: March 2026

Quick Answer

With ChangeThisFile, convert BMP to PNG directly in your browser using the Canvas API. PNG applies lossless compression to reduce file size by 50-80% without losing a single pixel of quality. Your files never leave your device, ensuring complete privacy. Free, instant, no signup required.

Free No signup required Files stay on your device Instant conversion Updated March 2026

Convert BMP to PNG

Drop your BMP file here to convert it instantly

Drag & drop your .bmp file here, or click to browse

Convert to PNG instantly

BMP vs PNG: Format Comparison

Key differences between the two formats

Feature	BMP	PNG
Compression	None	Lossless (DEFLATE)
Quality loss	None (raw)	None (lossless)
Typical reduction	Baseline	50-80% smaller
Transparency	Limited	Full alpha channel
Color depth	Up to 32-bit	Up to 48-bit
Compatibility	Windows apps	Universal
Best for	Legacy systems	Graphics, editing, web

When to Convert

Common scenarios where this conversion is useful

Lossless compression of legacy files

BMP files from older systems waste enormous amounts of disk space. PNG provides identical quality with 50-80% smaller file sizes - perfect for archiving without any quality sacrifice.

Preparing images for web use

BMP files can't be used on the web. Converting to PNG gives you a web-ready format with full browser support and much more reasonable file sizes.

Enabling transparency for editing

BMP has very limited transparency support. Converting to PNG lets you work with full alpha channel transparency in any modern image editor.

Cross-platform sharing

BMP is primarily a Windows format. PNG works on every platform - Windows, macOS, Linux, iOS, and Android. Convert for universal compatibility.

Who Uses This Conversion

Tailored guidance for different workflows

Designers

Convert BMP mockups to PNG for sharing with clients who need a universally compatible format
Transform BMP design assets to PNG for embedding in presentations or documents

Check the converted PNG at full zoom to verify no visible artifacts in gradients or fine details

Keep the original BMP as your master copy in case you need to re-export later

Web Developers

Convert BMP images to PNG for optimized loading on websites and web applications
Transform BMP assets to PNG for cross-browser compatibility in production builds

Test the converted PNG file in both Chrome and Safari to ensure consistent rendering

Consider the file size difference between BMP and PNG when optimizing page load speed

Photographers

Convert BMP photos to PNG for uploading to stock photography platforms or portfolios
Batch convert BMP images to PNG for delivering client galleries in a widely supported format

Use the highest quality setting when converting to PNG to preserve fine detail in your photos

Verify color accuracy after conversion, as BMP and PNG may handle color profiles differently

How to Convert BMP to PNG

1

Drop your BMP file

Drag and drop your BMP bitmap into the converter, or click browse to select it.
2

Lossless conversion

The browser reads the uncompressed BMP data and encodes it as a lossless PNG. Every pixel is preserved exactly.
3

Download the PNG

Save the PNG file. It's much smaller than the BMP but contains identical image data with no quality loss.

Frequently Asked Questions

Is BMP to PNG conversion truly lossless?

Yes. PNG uses lossless compression (DEFLATE algorithm), meaning every single pixel is preserved exactly as it was in the BMP. You can convert back and forth without any quality degradation.

How much smaller will the PNG be?

Typically 50-80% smaller for photographic content, and even more for simple graphics. A 15MB BMP screenshot might become 3-5MB as PNG. Graphics with large areas of solid color compress especially well.

Why not convert directly to JPG for even smaller files?

JPG offers smaller files but with lossy compression - you lose some quality. BMP to PNG preserves every pixel exactly. Choose PNG when quality matters, JPG when file size matters most.

Can I convert 32-bit BMP with alpha transparency?

Yes. If your BMP file contains alpha channel data (32-bit RGBA), the transparency will be preserved in the PNG output.

Is this useful for pixel art?

Absolutely. Pixel art needs lossless compression to maintain crisp edges and exact color values. PNG is the standard format for pixel art and BMP to PNG is a lossless conversion.

What about indexed color (8-bit) BMPs?

The converter handles all BMP color modes including 1-bit, 4-bit, 8-bit indexed, 24-bit, and 32-bit. The output PNG preserves the color information accurately.

Are my files safe?

Yes. All processing happens locally in your browser. No files are transmitted over the internet. This is safe for proprietary, medical, legal, or any sensitive images.

Does this work on macOS?

Yes. While BMP is associated with Windows, this converter works in any browser on any operating system - macOS, Windows, Linux, iOS, and Android.

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Need to convert programmatically?

Use the ChangeThisFile API to convert BMP to PNG in your app. No rate limits, up to 500MB files, simple REST endpoint.

View API Docs

Read our guides on file formats and conversion

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