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BMP to TIFF converter

Convert BMP images to TIFF format

No watermarkFree & unlimited
All processing happens in your browser. No data is sent to any server.

Both ends of this pair store pixels raw, so this is a container swap rather than a compression decision. The bitmap arrives as bottom-up BGR rows padded to a four-byte boundary; the TIFF leaves as top-down RGB in a single strip with a small tag directory in front. The pixel values are identical. What changes is which software will accept the file, since prepress, scanning and archival pipelines expect TIFF and many of them refuse a .bmp outright. Expect the output to be almost exactly the same size as the input.

Key facts about BMP to TIFF converter

Key facts about BMP to TIFF converter
Quality changeNone. No lossy codec is involved, so every pixel the browser decoded is written into the TIFF unchanged.
TIFF variant writtenBaseline little-endian: the II marker, version 42, ten IFD tags, PhotometricInterpretation 2 for RGB, eight bits per sample, three samples per pixel, chunky planar order.
Compression tagSet to 1, meaning stored. This page cannot produce an LZW, Deflate or JPEG-compressed TIFF.
Exact output size134 bytes of header and tag directory plus width times height times three. A 1920x1080 image is 6,220,934 bytes, 80 more than the same picture as a 24-bit bitmap.
Why sizes can differBitmap rows are padded to a multiple of four bytes while TIFF strips are not, so for other widths the TIFF is slightly smaller despite the bigger header.
TransparencyDropped. Three samples per pixel with no ExtraSamples tag, so a 32-bit bitmap loses its alpha and cleared pixels are written black.
Strips and pagesOne strip holding the whole image and one image file directory, so the result is single-strip and single-page with no tiling.
Opens the resultPhotoshop, GIMP, Affinity, ImageMagick, macOS Preview, Windows Photos, and the scanning and OCR tools that reject bitmaps.

What happens to your file

The TIFF is manufactured in your browser, byte for byte. Your bitmap is decoded by the browser image reader from an object URL and drawn onto a canvas, then read back as raw RGBA with getImageData. The page strips the alpha byte out of every pixel, writes a little-endian header and a ten-entry directory with a DataView, and appends the RGB bytes. No request is made to any server at any point.

About this tool

  1. 1

    Load the bitmaps

    Drop up to twenty .bmp files, each as large as 500 MB, or click to browse.

  2. 2

    Decide on dimensions

    Resize presets are the only lever on output size here, since there is no compression to tune. Leave them off for archival work.

  3. 3

    Convert

    Press Convert. Writing is fast because no encoder runs, just a memory copy and a header.

  4. 4

    Download the TIFF

    Save the file, or take the batch as converted-tiff-files.zip assembled in the browser.

Specs & compatibility
Input and outputTakes .bmp only (image/bmp) and returns .tiff with the image/tiff type; any other extension is refused before decoding.
Conversion pathBMP to TIFF runs in three steps: an <img> element decodes the bitmap, 24-bit and 32-bit variants alike; the pixels land on a 2D canvas in this tab; then getImageData feeds a baseline IFD writer that assembles the file in page memory.
Browser supportThe bitmap side decodes in every current browser, while writing the TIFF needs nothing from the browser, the directory being written in the page.
Controls for this pairNo quality slider, TIFF not being a lossy target here, so the max-dimension presets from 3840 down to 200 px are the only way to hold the TIFF down in size against the BMP.
Batch, caps and namingTwenty BMP files per run at 500 MB each; one result downloads as a single TIFF, several as converted-tiff-files.zip, zipped by JSZip 3.10 in page memory.
Device ceilingThe canvas caps it: past roughly 16,384 px a side Chromium refuses the bitmap and iPhone Safari gives up sooner, so an oversized BMP fails before any TIFF bytes exist.
  • Do not expect disk savings; if you want a smaller archive, zip the resulting folder, which compresses raw data well.
  • If the receiving tool complains, it almost always wants a compressed or multi-page TIFF, neither of which this writer produces.
  • Keep presets off when the TIFF feeds OCR, since resampling text costs recognition accuracy for no benefit.
  • A bitmap with an alpha channel should go to PNG instead, because this writer paints cleared pixels black.
  • Baseline uncompressed RGB TIFF output
  • Bit-exact pixel pass-through, no codec
  • Ten-tag little-endian IFD written in the page
  • Twenty bitmaps per run, zipped locally
  • Feeding bitmap scans into an OCR or document management system that only accepts TIFF.
  • Handing artwork to a prepress or print shop whose intake specification names TIFF.
  • Archiving uncompressed captures in a format professional imaging software reads without a plugin.
Almost never, and that is expected. Both formats store raw pixels, so the payload is width times height times three either way. The TIFF header and tag directory take 134 bytes against the bitmap 54, so for widths divisible by four the TIFF is 80 bytes larger. Bitmap row padding can tip it the other way on odd widths.
No. The writer always sets Compression to 1, meaning stored, with no option to change it. Compressed TIFF needs an LZW or Deflate implementation feeding a strip writer, which is different software. If the file must be small, compress it externally or pick PNG.
No. The directory chain terminates after the first image file directory, so every output is single-page. Converting twenty bitmaps gives twenty separate TIFFs inside a ZIP, not one twenty-page document. Merging them needs a dedicated tool such as ImageMagick.
The writer keeps only the red, green and blue bytes from each canvas pixel and ignores alpha. A fully transparent canvas pixel reads back as zero in all four channels, and zero in RGB is black. Ordinary 24-bit bitmaps never hit this, but a 32-bit source will.
No. The directory contains only the ten structural tags describing the pixel grid, and an ICC profile tag is not among them, so software will assume sRGB. That matches what the canvas produced, but colour-managed print work should not go through a browser canvas.

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