BMP to TIFF Converter

Convert BMP to TIFF Online

TIFF is the container that scanning, publishing, prepress and GIS workflows still standardise on, largely because it can hold anything: one image or hundreds of pages, bilevel or 16-bit-per-channel colour, compressed losslessly or not compressed at all. That flexibility is also the catch — a .tif is only as archival as the compression scheme you chose when you wrote it, and the choice is not obvious from the filename. This page walks through that decision with measured numbers, because it is the only setting on a BMP-to-TIFF conversion that materially changes what you end up with.

How to Convert BMP to TIFF

1. Upload Your BMP File: Drag your .bmp onto the page or click "+ Add Files". Several bitmaps can be queued and converted in one batch.
2. Choose a Compression Type: This is the setting that matters. Compression Type opens on JPEG, which is lossy and produces a small file. Pick LZW for the lossless, maximum-compatibility option, or NONE if a downstream tool insists on raw uncompressed strips.
3. Set the File Extension and Resolution (Optional): File extension opens on TIFF; switch it to TIF if a legacy tool only recognises the three-letter suffix. Image resolution opens on Keep original — switch to a percentage, one of the Preset Resolutions, or an explicit Width x Height to scale in the same pass. Quality Preset opens on "Very High (Recommended)" and sets the quality level used by the lossy schemes.
4. Convert and Download: Click Convert and save the .tif. Files are uploaded over an encrypted connection, processed on our servers, and deleted automatically after a few hours — no sign-up, no watermark, never shared or made public.

Compression Types Compared, With Measured Sizes

Every number below comes from the same source file: a 1920 x 1080 24-bit photographic bitmap measuring 6,220,854 bytes, encoded through our own pipeline at the default "Very High" quality level for the lossy schemes. "Pixel-exact" means the decoded output compared byte-for-byte against the bitmap with zero differing pixels.

Choosing Between Them

• Archiving, master copies, anything you might re-edit: choose LZW. It is lossless, it is what almost every TIFF reader expects, and the size penalty against the smaller lossless options is modest. Deflate is a reasonable alternative if you know your readers handle it.
• Photographs where the file has to be small: the default JPEG setting is doing exactly what you want — 1.39 MB against 2.97 MB for LZW in the test above. Just be aware it is genuinely lossy and re-saving repeatedly will accumulate damage.
• Scanned text, line art, and 1-bit documents: LZW is the pick here. CCITT Fax 4 is what fax and document-imaging systems use for bilevel pages, but it needs a genuine 1-bit source and this page has no bilevel conversion, so a 24-bit or greyscale bitmap sent to it leaves a truncated, unreadable file instead of a clean error.
• Flat graphics and screenshots: PackBits is a simple run-length scheme that works well on large areas of identical colour. On our photographic test image it produced a file about 48,000 bytes larger than the uncompressed version, which is exactly the failure mode run-length encoding is known for.
• Anything going to a printer, a publisher or a client: stick to LZW or NONE. WebP-in-TIFF and JP2K-in-TIFF are legal but many readers, including plenty of professional printing software, will simply refuse to open them.

BMP and TIFF Side by Side

Frequently Asked Questions

Is the default TIFF output lossless?

No, and this catches people out. Compression Type opens on JPEG, which is a lossy scheme carried inside the TIFF container. In our testing, our 1920 x 1080 photographic bitmap dropped from 6,220,854 bytes to 1,392,175 bytes at the default settings — an excellent result, but the decoded pixels no longer match the source. If you need an exact copy, change Compression Type to LZW: the same image produced a 2,970,356-byte file that compared byte-for-byte identical to the bitmap, with zero differing pixels.

What is the difference between .tif and .tiff?

Nothing except the number of letters. Both suffixes name the same tagged image file format, and the bytes inside are identical. The three-letter form is a survivor of the old DOS 8.3 filename limit and is still what many Windows and scanning tools write by default. Use the File extension control to pick whichever one your downstream software expects; if you are not sure, .tif is the more conservative choice with old applications.

Why is my TIFF sometimes bigger than the original BMP?

Because two of the schemes genuinely can be. Choosing NONE stores the same raw pixels the bitmap did, plus TIFF's tag directory, so the file lands a couple of hundred bytes above the source. PackBits is worse: it is a run-length encoder, and run-length encoding expands data that has no runs. On our photographic test image PackBits produced 6,268,684 bytes against 6,220,854 for the source bitmap. Both are correct behaviour; they are simply the wrong choices for a photograph.

Can I put several bitmaps into one multi-page TIFF?

Multi-image TIFF is a core feature of the format — a single file can hold many image directories, which is how scanned documents are usually stored. This converter produces one .tif per uploaded bitmap. If your goal is a single paginated file from several scans, BMP to PDF is the more practical route: it merges everything into one document by default and opens in any PDF reader without specialist software.

Does TIFF keep transparency from a 32-bit bitmap?

TIFF can store an alpha channel, so transparency is representable in the output. Whether it survives your specific downstream tool is a separate question: plenty of prepress and printing applications either ignore TIFF alpha or composite it against white without asking. Most .bmp files use the plain 40-byte BITMAPINFOHEADER and are fully opaque anyway. If transparency is the point of the file rather than an incidental detail, BMP to PNG or BMP to WebP will behave far more predictably.

Which compression should I use for scanned documents?

Use LZW — it keeps greyscale and colour scans pixel-exact and every imaging system reads it. CCITT Fax 4 is the classic choice for genuinely bilevel page images, but it needs a 1-bit source and there is no bilevel conversion on this page, so pointing a colour or greyscale bitmap at it leaves a truncated, unreadable file rather than reporting an error. Leave the JPEG setting the dropdown opens on only when the scan is photographic and file size is the binding constraint.

Will the TIFF open on a Mac, in a browser, or on a phone?

macOS Preview handles TIFF natively, and so do the standard image viewers on most Linux desktops. Browsers are the weak spot: TIFF is not a format browsers are expected to render, so a .tif link will usually download rather than display. Phones vary and often need a third-party viewer. If the image has to be viewable by anyone with a link, convert to PNG or WebP instead and keep the TIFF as your master.

Does converting to TIFF improve the image in any way?

It cannot. A conversion never adds detail that was not in the source, and choosing a lossless scheme simply means nothing is lost. What TIFF gives you over BMP is not quality but capability: real compression choices, extensive metadata tags, multi-image support, and higher bit depths than a bitmap can describe. If the bitmap is a low-resolution screenshot, the TIFF will be a low-resolution screenshot with better packaging.

Should the file size still be smaller after this conversion?

Usually yes, and by a lot, because an uncompressed bitmap is close to a worst case. BMP stores three bytes per pixel with every row padded up to a 4-byte boundary, which is why our 1920 x 1080 test file measures exactly 6,220,854 bytes — 1,080 rows of 5,760 bytes plus a 54-byte header. Every lossless scheme except NONE and PackBits cut that by more than half in testing, and the default JPEG setting cut it by just under 78%. If you have existing TIFFs that need shrinking rather than converting, Compress TIFF is the dedicated tool.