Convert BMP to PNG Online Free

Turn .bmp files into PNG without losing a single pixel — identical image, much smaller file. Supports batch conversion with ZIP download. No sign-up, no file upload.

Drag one or more BMP files here

or click to browse — multiple files supported · also accepts PNG, JPG, and WebP by drag-and-drop

Convert to

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PNG —

Original format

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Final format

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Original size

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Final size

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BMP or PNG: the zero-loss conversion

BMP and PNG share something important: neither one discards any image information. The difference is in how they store that information. BMP simply writes the color of every pixel, one by one. PNG applies a compression algorithm that identifies patterns and repetition to take up less space.

The result is that converting BMP to PNG delivers an image that is pixel-for-pixel identical to the original, but taking up a fraction of the space. In screenshots and drawings, the reduction passes 80%. It’s rare to find a decision this simple: there’s no quality trade-off at all in this conversion.

Beyond size, PNG also wins on compatibility and longevity. It’s an open format, displayed by any browser, editor, or app, and supports transparency in case the image gets edited later. BMP, on the other hand, has several old variants that not every modern program reads correctly — making it a poor choice for long-term archiving.

Criterion	BMP	PNG
Quality loss	None	None
Compression	Practically none	Lossless, efficient
Typical screenshot	Reference	Up to 80% smaller
Transparency	No (in practice)	Yes
Browser support	Inconsistent	Universal
Suitable for archiving	No	Yes

Why use this converter?

Total privacy

Conversion happens right in your browser. No file is ever sent to an external server.

Batch conversion

Select dozens of images at once and download them all converted in a single ZIP file.

Instant preview

See the converted image before downloading, with the final size shown in real time.

Works offline

Once the page has loaded once, the tool keeps working even without an internet connection.

How to convert BMP to PNG step by step

The first step is loading your files. Drag the .bmp images into the dashed area at the top of the page, or click it to open your system’s file picker, already filtered to show only BMP files. There’s no limit on quantity or size — a relevant detail here, since BMP files tend to be several megabytes and many online tools refuse uploads that large. Since nothing is sent to a server, file size is never a problem. Conversion starts on its own as soon as the files come in.

With a single file, the tool opens in Single image mode, showing a preview of the generated PNG along with four indicators: original format, final format, original size, and final size. Since both ends are lossless formats, the preview image is exactly the same as the original — only the final size number changes. With two or more files, the tool automatically switches to Batch mode, with a table showing each image’s name, size before and after, and a status dot that turns green as each item finishes.

The target format on this page is already set to PNG, so there’s nothing to adjust to preserve quality. If your images happen to be photos and the PNG still ends up too heavy for your needs, click JPEG in the buttons above the preview: the conversion redoes itself instantly, producing much smaller files in exchange for a small loss. The switch doesn’t require reloading the page or reselecting the files. The two buttons at the top of the panel also switch manually between single and batch mode.

Finally, download the result. In single mode, use the Download converted image button. In batch mode, the Download all converted (ZIP) button bundles everything into one compressed file — handy if you’re converting an entire archive of scans. If you only want part of the images, each table row has its own download button and an X to discard that item before generating the ZIP. All conversion runs inside the browser, with no upload.

Frequently asked questions

Does converting BMP to PNG lose quality?

No, none at all. Both formats are lossless: PNG stores exactly the same pixels as the original BMP, just using a compression algorithm that BMP doesn’t have. The resulting image is pixel-for-pixel identical — just much smaller.

How much smaller does the file get when converting BMP to PNG?

It depends a lot on the content. In screenshots, drawings, and images with flat color areas, the reduction easily passes 80%. In photos with lots of detail and gradients, the gain is smaller, between 40% and 60%, because PNG’s algorithm performs better on repeated color regions.

When should I choose PNG over JPG when converting a BMP?

The practical rule is to look at the image content. If it’s a screenshot, drawing, chart, pixel art, logo, or anything with text and sharp edges, choose PNG: it preserves every line precisely and doesn’t create the blurring typical of JPEG compression. If it’s a photo or a colorful scan without small text, JPG delivers much smaller files with negligible visual difference.

Will the generated PNG have a transparent background?

Not automatically. PNG supports transparency, but the source BMP almost never carries an alpha channel — so the converted file keeps the solid background that was already in the image. Converting to PNG only enables the possibility of transparency in future edits. To actually remove the background, use the background remover tool after conversion.

Can I convert several BMP files to PNG at once?

Yes. Drag as many files as you want — the tool automatically switches to batch mode, converts all of them, and makes the ZIP download available. Each row in the table also has its own download button.

I need to archive old BMP scans. Is it worth converting them to PNG?

Definitely, and it’s one of the best uses for this conversion. Since PNG is lossless, you reduce the space used on disk or in backups without sacrificing a single pixel of the original — unlike converting to JPG, which would discard information irreversibly. PNG is also an open, widely supported format, which lowers the risk of the file becoming unreadable years from now, something that’s already starting to happen with old BMP variants.

Does the tool work on mobile?

Yes. It works in any modern browser — Android, iPhone, tablet, or computer — no app install needed.