What is a TIFF file, and why will nothing open yours?
A TIFF is a box with a label listing what is inside it. The picture in the box can be stored half a dozen different ways, and a program that reads TIFF often means it reads some of them. That is the whole reason one TIFF opens fine and the next one, from the same scanner, does not.
The name is literal: Tagged Image File Format. The file starts with a list of numbered tags saying how wide the image is, how many bits a pixel uses, which compression was applied, whether white is zero. A reader walks that list and then decodes the pixels however the tags told it to.
The same picture, six ways
One 1200 by 630 image, converted on 2026-09-12 with sips and libtiff's tiffcp:
| Stored as | Bytes | Notes |
|---|---|---|
| TIFF, Deflate | 15,138 | Same algorithm as a PNG or a ZIP. |
| TIFF, LZW | 34,084 | The common one. Lossless. |
| TIFF, PackBits | 2,237,976 | Run-length. Only helps on flat areas, and this image has few. |
| TIFF, uncompressed | 2,271,494 | Every pixel, written out in full. |
Fifteen kilobytes to 2.3 megabytes. Every one of those is a valid TIFF of the same image. The uncompressed figure is not mysterious: 1200 x 630 x 3 is 2,268,000 bytes of pixels, and the remaining 3,494 are the tags.
Why your browser will not show it
No browser decodes TIFF. Not Chrome, Firefox, Safari or Edge. They all handle JPG, PNG, WebP, GIF and AVIF, and none of them handles this one, which is why double-clicking a TIFF downloads it rather than opening a tab, and why a TIFF you email somebody is a TIFF they cannot look at.
This is not an oversight. TIFF is a format for producing files, not for delivering them: one file can hold multiple pages, 16 bits per channel, CMYK ink values for a printing press, an alpha channel, and layers of metadata. Supporting all of that in a browser buys nothing, because nobody publishes a TIFF on a web page.
Where TIFFs come from
Three places, mostly. Document scanners and fax machines, which produce black and white pages, often several to a file, usually compressed with CCITT Group 4. Cameras and film scanners, where a TIFF is the uncompressed master you edit before exporting a JPG. And print production, where CMYK and precise colour profiles matter and JPG is not good enough.
If your TIFF came from the first group, it is probably several pages and probably CCITT. That is worth knowing, because it is the variety most likely to be refused by a converter. Ours decodes Group 3 and Group 4, so a single page fax opens; a multi-page one still has to be split first.
Is .tif different from .tiff?
No, and for exactly the reason JPG and JPEG are the same file. MS-DOS allowed three characters after the dot, so the four letter extension was cut to three, and both spellings survived. The bytes are identical and any reader takes either.
What to convert it to
PNG if you will edit it again or it has transparency. Both are lossless, so nothing is thrown away and the file can go round again without degrading.
JPG if it is a photograph or a scan you just need to send, upload or look at. It is far smaller and everything opens it. You lose a little detail once, permanently, which for a document scan does not matter and for a photographic master does.
Keep the TIFF if it is 16 bit, if it is CMYK for print, or if it is the only copy of something scanned at high resolution. Convert a copy and leave the original alone.
Open one
Both of these decode the TIFF in your browser, on your machine, with nothing uploaded. If a file is refused they say which part of it they could not read rather than handing back a blank image.
filetity is built by Adarsh Mishra. The byte counts above are from one image converted on 2026-09-12 and will differ with yours; the range between the smallest and largest will not. Corrections welcome: support@filetity.com.