A JavaScript TIFF decoder, because the browser will not do it
Most raster converters on this site lean on the browser’s own image decoders, which handle JPEG, PNG, WebP, AVIF and BMP without any help. TIFF gets no such help: it was never a web format, and this tool does not assume the browser can read one. It is not alone in that. HEIC to JPG ships its own decoder for the same reason, because browsers do not read HEIC either.
Instead it loads a small pure-JavaScript TIFF decoder, utif2, the first time you run a conversion. That library parses the file structure itself, walks the image directories, decodes each one to raw pixels, and hands the result back as plain RGBA data. Those pixels are then written onto a canvas and encoded as JPEG, which is the one part of the pipeline the browser does do natively. There is no WebAssembly involved and no download of a large runtime; it is ordinary JavaScript that arrives with the page’s own assets.
The practical consequence is that TIFF support here is defined by that decoder rather than by your browser version, which is why the next section matters.
Compression schemes the decoder recognises
TIFF is less a format than a filing system for images. The header points at a list of directories, each directory describes one image, and one of its fields says how the pixel data was compressed. The list of legal values is long and has grown for forty years, which is why one program’s TIFF opens fine in another and the next one does not.
The decoder used here handles the schemes you are realistically going to meet: uncompressed, LZW, PackBits, Deflate, CCITT Group 3 and Group 4 fax encoding, and both the old-style and modern JPEG-inside-TIFF variants. It additionally recognises several camera raw schemes, including Nikon, Panasonic, Sony and the ThunderScan and LogLuv encodings, which covers a surprising amount of scientific and archival material.
What it does not cover, it does not shout about. An unrecognised compression value is reported to the browser console and that page’s pixel buffer is left full of the zeros it was allocated with, which means you get a page of flat colour rather than an error. On the usual RGB and black-is-zero scans zero reads as black, so the page arrives solid black; on a white-is-zero scan, which is how a lot of fax and bilevel material is stored, the same zeros read as white and the page arrives blank. Either way it is easy to misread as a broken tool when it is really an unsupported encoding. Re-saving the file as uncompressed or LZW from whatever produced it resolves it every time.
Multi-page TIFFs and the ZIP you get back
TIFF’s directory structure is why a single .tif can hold a whole stack of scanned pages, and document scanners lean on that constantly: a signed contract, a bundle of receipts, an incoming fax, a batch of forms fed through a sheet feeder. Each page is a separate directory inside one file.
Every page is decoded and converted here, not just the first. A single-page file gives you one JPG named after the source. A multi-page file gives you one JPG per page, named with the original base name plus a zero-padded page number so that page 2 sorts before page 10, and all of them are bundled into one ZIP so the whole document arrives in a single download. Directories that carry no usable image dimensions are skipped rather than producing an empty file, and if nothing at all decodes the run stops with an error instead of handing you an empty archive.
The progress bar reflects that two-stage shape. Decoding and encoding the pages fills the first ninety-five percent, and the remaining sliver is the archive being written once every page is finished.
Converting one TIFF at a time
- Drop a
.tifor.tiffonto the box above, or click Choose a file. This tool takes one file per run; dropping several keeps only the first. - Pick a JPG quality preset. Balanced (recommended) is right for reading and sharing; High (largest file) is worth the bytes for a scan that will be printed or put through text recognition.
- Click Convert TIFF to JPG. A large multi-page scan takes a while, because every page is decoded and re-encoded individually on your own processor.
- Download the JPG, or the ZIP if the file had more than one page, and then click Process another before loading the next document.
Grayscale, CMYK scans and transparent regions
TIFF stores what each sample means in a separate field, and the decoder handles the common interpretations: black-is-zero and white-is-zero grayscale, full RGB, palette colour and CMYK. That last one matters for prepress work, where scanners and layout software routinely produce CMYK TIFFs. The conversion to RGB is done with a plain formula rather than a colour-managed transform through the file’s embedded profile, so expect a visible but modest shift on a press-ready file. It is fine for proofing and wrong for colour-critical work.
Transparency is the other case to know about. A TIFF exported from design software can carry an extra alpha sample, and unlike the PNG and WebP converters this page does not paint a background colour under the image before encoding. JPEG cannot store alpha, so those regions come out dark instead of white. Scanner output never has an alpha channel, so this only affects files that came out of an editor.
Blank pages, and what they mean
If a page arrives as flat colour, black or white with nothing on it, work through three possibilities in order. The likeliest is an unsupported compression scheme, described above, and the browser console will name the value it did not recognise. The second is a TIFF whose pixel data has been stored in an unusual bit depth or sample layout that the decoder cannot map onto ordinary RGBA. The third, on very large multi-page scans, is simply memory: both the decoded pages and the finished JPGs live in the tab at once, and a laptop with limited memory converting a hundred-page archive can run out.
In all three cases the fastest route is to re-export the TIFF from the software that created it with a common compression setting, or to convert the document to PDF and use PDF to JPG instead, which takes a completely different path through the file. Image Converter covers the other odd source formats that turn up in scanning workflows, the wider set of tools is on the image tools hub, and the image converter and editing guide explains which format to keep an archive in.