PNG to BMP

PNG to BMP is a free tool that converts a PNG image file into a BMP bitmap file in your browser.

Browser-based PNG-to-BMP conversion

You can convert a PNG image into a BMP file in your browser.

PNG-to-BMP conversion is done entirely in your browser. Your PNG is never uploaded to a server, which is useful when the image contains internal diagrams, unreleased artwork, account screenshots, or other material you do not want transferred to a conversion service.

Is BMP the right destination for your PNG?

BMP is the right destination when a Windows application, older graphics program, device driver, or legacy workflow specifically requires a bitmap file. BMP stores raster pixel data in a straightforward format that many older systems understand.

For websites, email, and routine image sharing, keeping the PNG usually makes more sense. PNG has broad browser support, preserves transparency, and commonly uses much less storage. Converting a PNG to BMP also does not improve its visual quality. If the PNG was created from a compressed JPG, saving it as a lossless BMP cannot restore details already removed by JPG compression.

PNG and BMP format differences

PNG and BMP can represent the same raster image, but they store it differently and are intended for different environments.

How much larger will the BMP file be?

The BMP will commonly be several times larger than the PNG, but the exact difference depends on image dimensions, BMP bit depth, and how efficiently the original PNG compresses.

An uncompressed 24-bit BMP needs about three bytes per pixel, plus row padding and a header. For example, a 1,200 by 800 image contains 960,000 pixels. Its 24-bit pixel rows require 2,880,000 bytes, so the completed file will be roughly 2.9 MB. A 32-bit representation would require about 3.84 MB for pixel data before accounting for its header.

• A flat-color interface icon may have a very small PNG because repeated colors compress well, while its BMP remains tied mainly to pixel count.
• A detailed 4,000 by 3,000 image can produce a BMP measured in tens of megabytes, even when the PNG is much smaller.
• Changing the PNG or BMP filename or its length has no meaningful effect on image storage. BMP storage depends mainly on width, height, bit depth, and compression.

Check available disk space for the generated BMP before converting very large PNGs. Generating a BMP in the browser also uses local memory, so extremely large pixel dimensions can place more strain on a phone or older computer than the source PNG file size alone suggests.

What happens to transparency and unusual PNGs?

Transparency, animation, high bit depth, and color metadata may not transfer consistently because BMP support varies across encoders and receiving applications. Inspect the saved BMP in the software where it will actually be used.

A PNG with an alpha channel can contain fully transparent and partially transparent pixels. Although some BMP variants can store alpha values, many older programs treat BMP as opaque. They may display transparent areas against black, white, or another solid color.

An animated APNG needs special attention because BMP has no standard animation model. A format conversion can only produce a still BMP image unless another workflow exports individual frames. PNG files can also use indexed palettes, grayscale samples, 16-bit channels, embedded color profiles, and non-Latin filenames. BMP has several header and bit-depth variants, but older receiving software may accept only a limited subset. Filename characters are separate from image encoding, though scripts and legacy applications that consume BMP files may still mishandle spaces or accented characters in file paths.

Common questions about PNG-to-BMP conversion

Can I convert a PNG by renaming the file extension?

No. Renaming image.png to image.bmp changes only the name, not the encoded image data. Software that checks the file header will still identify it as PNG, and some applications will report an invalid or unsupported file.

Can BMP store a limited color palette?

Yes. BMP supports indexed-color variants with palettes as well as true-color pixel formats. If an older application requests a particular color depth, such as 8-bit or 24-bit BMP, a general format conversion may not satisfy that requirement unless the resulting file uses the expected variant.

Why can BMP pixel rows appear upside down in custom code?

Many BMP files store pixel rows from bottom to top, unlike the top-to-bottom order developers often expect. Some BMP headers also allow top-down storage by using a negative height value. Code that reads raw BMP data must check the header rather than assuming one orientation.

Can I convert the BMP back to PNG later?

Yes, BMP pixel data can be encoded as PNG again, often with a substantial reduction in file size. However, transparency, color precision, metadata, or animation discarded during the first conversion cannot be recreated merely by converting back.

Should I use BMP in Microsoft Office files?

Many desktop Office applications can import BMP, but PNG is generally more compact and more dependable when transparency is needed. Use BMP when a template, macro, add-in, or recipient explicitly requires it, then open the document on the target system to confirm that it displays correctly.

Checks before handing off the file

• Open the BMP in the exact application or device workflow that requested it.
• Confirm that transparent areas have an acceptable background.
• Compare the pixel dimensions with the source PNG.
• Zoom in on gradients, text, and thin lines in the BMP to check for color-depth issues.
• Verify that the larger BMP fits any storage, attachment, or import limit of the receiving application.

If the BMP requirement disappears, keep the original PNG as the archival copy. For a smaller web image, PNG to WebP may be a better next step, while PNG to JPG fits photographs where transparency is unnecessary and some lossy compression is acceptable.