BMP to PNG converter

BMP → PNG compressed our 80×50 Windows BMP from 12,054 bytes to a 501 byte PNG without changing dimensions.

Converted with Image engine · nothing stored
Free: 5 conversions a day · 5 MB each
Higher limits →

From real runs

What you get — and what changes

Element	Result	What happens
Pixel dimensions	Kept	The 80×50 BMP opened as an 80×50 PNG after conversion.
RGB colors	Kept	The blue center region and pale corner colors sampled as the expected RGB values in the PNG.
Compression	Changed	The uncompressed 12,054 byte BMP shrank to 501 bytes through PNG compression.
Alpha channel	Lost	The tested BMP was 24-bit RGB, so the output PNG was RGB and did not invent transparency.
Resolution metadata	Changed	BMP pixel-per-meter metadata was not exposed as a matching PNG metadata field in our inspection.
Editability	Kept	The PNG is still a raster image, suitable for pixel editing but not vector or layer editing.

Pixel dimensions Kept
The 80×50 BMP opened as an 80×50 PNG after conversion.
RGB colors Kept
The blue center region and pale corner colors sampled as the expected RGB values in the PNG.
Compression Changed
The uncompressed 12,054 byte BMP shrank to 501 bytes through PNG compression.
Alpha channel Lost
The tested BMP was 24-bit RGB, so the output PNG was RGB and did not invent transparency.
Resolution metadata Changed
BMP pixel-per-meter metadata was not exposed as a matching PNG metadata field in our inspection.
Editability Kept
The PNG is still a raster image, suitable for pixel editing but not vector or layer editing.

Sample conversions

Windows bitmap badge

Input: An 80×50 24-bit BMP with a blue rectangle, pale background, and white BMP text, 12,054 bytes.
Output: A 501 byte RGB PNG at the same dimensions. The center sampled near the same blue as the input.

Legacy app screenshot

Input: A BMP screenshot exported by an old Windows tool with flat colors and no alpha channel.
Output: A much smaller PNG appropriate for web upload. It stayed a screenshot, not editable UI text.

A real BMP → PNG run

We converted our BMP sample (703 KB) with Image engine on 2026-10-20. It took 62 ms and produced a 19 KB PNG file, 97% smaller than the input. The engine raised 1 warning, listed below.

Input · sample.bmp · 703 KB

600 × 400 px, 24-bit

Width: 600
Height: 400
Encoding: 24-bit

Output · sample.png · 19 KB

600 × 400 px, 8-bit, colour type 2

Width: 600
Height: 400
Encoding: 8-bit, colour type 2

Image metadata stripped from output.

Is your file a scan?

A BMP scan converted to PNG is still a raster page. Use OCR-oriented workflows if the important output is text, fields, or table values.

Options and when to change them

width: Resize the BMP while converting if the original came from a large screen capture.
height: Use with width for exact PNG dimensions, or leave unset to keep the bitmap ratio.
fit: Choose contain for padded output, cover for a cropped thumbnail, and fill for exact stretching.

Do it yourself

ImageMagick 7

bash

magick in.bmp out.png

PNG compression keeps raster pixels losslessly, but it does not recover layers or text from a screenshot.

BMP to PNG by API or MCP

The HTTP API and the MCP server run the exact engine this page uses (Image engine); the response carries the same warnings the web converter shows. Check support first with GET /api/v1/pairs?from=bmp&to=png.

curl

curl -X POST https://filetypeconverters.com/api/v1/convert \
  -H "Authorization: Bearer $FTC_API_KEY" \
  -F "file=@input.bmp" -F "from=bmp" -F "to=png" \
  -F 'options={"dpi":96}' \
  --output output.png

Options this engine accepts for BMP → PNG

Key	Applies to	Type	Default
dpi	Reading BMP	number	96
width	Writing PNG	number	0
height	Writing PNG	number	0
fit	Writing PNG	contain · cover · fill	contain
quality	Writing PNG	number	90
background	Writing PNG	string	#ffffff
stripMetadata	Writing PNG	boolean	true

API reference

When this is the wrong conversion

Use BMP → JPG for photo-like bitmaps when smaller opaque photo output matters more than lossless pixels.
Keep BMP if an old application specifically requires Windows bitmap input.
Use OCR if the BMP is a screenshot and the words need to become text.

BMP to PNG questions

Is BMP → PNG lossless?

For the tested 24-bit BMP, PNG preserved the raster content without a lossy compression step. Metadata and application-specific BMP details are a separate issue.

Why did the BMP shrink so much?

BMP is often uncompressed. Our simple 12,054 byte bitmap became a 501 byte PNG because flat regions compress well.

Will BMP → PNG create transparency?

No. The RGB BMP produced an RGB PNG. Transparency only exists if it is present and supported in the source data path.