BMP to TIFF, lossless and private. Nothing ever uploads.

Drop BMP scans or photos below — get a TIFF per file with LZW compression and print-ready DPI tags, in batches of up to 20. Converted entirely on your device.

Your file data never leaves the device
LZW / Deflate / PackBits / uncompressed
Batch up to 20 files + ZIP
Multi-page TIFF combine + DPI tags to 600

Privacy you can verify, not just trust

Most online BMP converters upload your scans to their servers first — and some keep a download link live for hours afterwards. This one can't: the BMP decoder and the TIFF encoder both run entirely in your browser. Your file data never leaves the device — the only third-party requests are the site's own analytics, which count page views — and it uploads nothing, ever. There is no decoder to download and no file fetched after load for the conversion itself. Don't take our word for it:

New cross-origin requests during use: 0

Press F12 to open developer tools, then the Network tab.
Convert any BMP above. Watch: apart from the site's analytics, nothing new is requested — no uploads, and no file data ever leaves your device.
Extra credit: disconnect your internet after this page loads — conversion still works.

How to convert BMP to TIFF without uploading it

Every "free" online BMP converter you've used uploads your scans to a company server, converts them there, and — in several documented cases — keeps a copy or a live download link for hours. For scans of documents, photos and anything you wouldn't post publicly, that's an unnecessary risk. The safer approach is to convert the file where it already is: on your own device.

This tool does exactly that. When you drop a BMP here, your browser:

Decodes the BMP with pure JavaScript — paletted 1-bit, 4-bit and 8-bit images, 16-bit 555/565, 24-bit and 32-bit, top-down or bottom-up — so there is no decoder file to download and no waiting for a library to load. RLE-compressed BMPs are refused with the reason stated, instead of failing silently.
Flattens any transparency onto a white background, because the TIFF written here stores 8-bit RGB with no alpha channel. The file card warns you when this happens.
Re-encodes the pixels as a TIFF with a pure-JavaScript TIFF encoder — little-endian header, one IFD per image, LZW, Deflate, PackBits or no compression, and the DPI you chose written as XResolution and YResolution tags. Your original file is never modified.

What makes this converter different

The converters that top the results for this search mostly upload your files to a server (Convertio and CloudConvert both convert server-side, with free-plan caps and accounts), and the client-side ones we found are thin — filevolve converts locally in a batch but offers no compression choice, no DPI tags and no multi-page mode, tweakfiles is batch-only with no stated compression, DPI or multi-page options, PureConverter runs ImageMagick in WebAssembly with no stated compression, DPI or multi-page options, imageconvertit caps free conversions at 3 trial files (Pro allows 50), devokk converts one file at a time with uncompressed output and no DPI choice, and toolsmonk is a generic all-formats hub rather than a dedicated BMP-to-TIFF page. This page is the only fully client-side dedicated BMP-to-TIFF page we found that combines a batch of 20 files with a ZIP download, a genuine compression choice (LZW by default, Deflate, PackBits or uncompressed), DPI tags from 72 to 600, a multi-page TIFF combine mode, and no daily limits, no account, no watermark and no paywall. It runs entirely in your browser — there is no server to upload to, no daily limits, no account and no watermark.

When is TIFF the right choice for a BMP?

When the destination demands it: print shops and scanning bureaus that ask for TIFF, archives that store images losslessly, and layout software (InDesign, QuarkXPress and their peers) that places TIFFs at a stated DPI. TIFF is also the format for multi-page scans — one file, one page per image. BMP itself is already lossless, so the gain is not quality — it is compression (an LZW or Deflate TIFF is usually smaller than the BMP), DPI tags, and a format the print world accepts. For anything else — sharing, web, storage — keep the BMP or use BMP to JPG instead and keep the smaller file.

Files are checked by their contents, not their name: a BMP saved as .txt still converts, because the BM magic bytes are what matter, while a JPG renamed to .bmp is refused with a pointer to the matching converter. A corrupt or truncated BMP is refused at decode time, with a per-file error explaining what happened.

Honest limitations

No quality gain

BMP is already lossless — it stores every pixel exactly. A TIFF holds the same pixels, losslessly compressed; it cannot add detail that was never there.

TIFFs are usually smaller than BMPs

Expect a compressed TIFF to be smaller than the BMP it came from, because BMP stores every pixel raw. An uncompressed TIFF is about the same size as the BMP. Every file shows its size multiple honestly, and the batch bar shows the total before you download anything.

8-bit RGB only, alpha flattened

Output is 8-bit RGB — no 16-bit, no CMYK, no alpha channel. 32-bit BMP transparency is flattened onto a white background, and 16-bit BMPs are decoded down to 8-bit RGB.

RLE-compressed BMPs are refused

BI_RLE8 and BI_RLE4 BMPs — the old run-length encoding some scanners and old editors write — are not decoded. The file card says so plainly; re-save the BMP uncompressed (for example, open it in Paint and save as 24-bit BMP) and try again.

Multi-page TIFFs are not universal

Multi-page TIFFs open in most viewers, but some old software shows only the first page. If the destination is old or unknown, send one TIFF per file instead.

DPI is only a tag

The DPI you pick never changes the pixels — it only records how large the image prints. A 72-DPI tag on a 4000-pixel scan still prints large; the pixels are what they are.

Metadata is stripped

BMPs carry almost no metadata, and what little there is (DPI hints in the header) is dropped on re-encode — only the DPI you choose is written. There is no text layer, no OCR, and nothing searchable is added.

Frequently asked questions

Do my BMP files get uploaded anywhere?

No. The BMP decoder and the TIFF encoder both run entirely in your browser, so your file data never leaves the device. The only third-party requests are the site's own analytics, which count page views. You can verify it in your browser's Network tab, or disconnect from the internet after the page loads — conversion still works.

Will converting BMP to TIFF improve the quality?

No. BMP is already lossless — it stores every pixel exactly as scanned or drawn, with no compression at all. A TIFF holds exactly the same pixels, so converting cannot add detail that was never there. What TIFF adds is lossless compression, which shrinks the file, plus DPI tags and a format print shops and archives actually accept — converting to TIFF only stops further loss, it never improves the picture.

Should I choose LZW, Deflate, PackBits or no compression?

LZW is the default and the right choice for almost everything: it is lossless, it shrinks scans and photos well, and it is the prepress standard every print shop and layout program reads. Deflate is also lossless and usually makes the smallest files, but some very old software cannot read it. PackBits is a simpler lossless RLE format for very old software that does not understand LZW or Deflate. Uncompressed stores every pixel as 3 bytes with no compression at all — the largest files, useful only when the destination cannot decode any compression.

Which DPI should I choose?

DPI is only a tag — it never changes the pixels, it tells print shops and layout software how large the image prints. 72 DPI is for screen use, 150 DPI is fine for drafts and large prints, 300 DPI is the print standard, and 600 DPI is for high-resolution print work. A 300-DPI A4 scan is 2480 x 3508 pixels, about 26 MB uncompressed, so LZW or Deflate matters at high DPI.

What is a multi-page TIFF and when should I combine files?

A multi-page TIFF is one file holding several images, one per page — the format scanners and archives use for a document of many pages. Choose the combine mode when the BMPs belong together as one document, for example the pages of a scan, and keep one TIFF per file when each image is separate. Multi-page TIFFs open in most viewers, but some old software shows only the first page.

What happens to 16-bit, paletted or RLE-compressed BMPs?

Paletted BMPs (1-bit, 4-bit and 8-bit) and 16-bit BMPs convert fine: palettes are expanded to full RGB pixels with the colours preserved exactly, and 16-bit pixels are decoded down to 8-bit RGB, so the extra precision is lost. RLE-compressed BMPs (BI_RLE8 and BI_RLE4, the old run-length encoding some scanners and old editors write) are refused with a clear per-file message — re-save the file uncompressed, for example by opening it in Paint and saving as 24-bit BMP, and try again.

Does converting keep BMP transparency?

No. TIFF as written here stores 8-bit RGB with no alpha channel, so transparent areas in a 32-bit BMP are flattened onto a white background — the tool warns you on the file card when it finds transparency. If you need the transparency kept, convert to PNG instead with our BMP to PNG converter.

Why is the TIFF a different size from the BMP?

A BMP stores every pixel raw with no compression at all, so it is already as large as the format gets — a 1920x1080 BMP is about 6 MB. A TIFF with LZW or Deflate compression stores the same pixels losslessly in less space, so it is usually smaller than the BMP, not larger. An uncompressed TIFF is about the same size as the BMP. This tool shows the original and TIFF size for every file, with the size multiple, so the trade-off is never hidden.