File Formats
What Is TIFF? The Scanning, Print and Archive Format
TIFF is the lossless image format of scans, print files and archives. We explain its structure, compression options and how to convert large TIFF files.
Author: Hemen Dönüştür Editör EkibiPublished: 8 min read
TIFF is the common language of scanned documents, professional photographs, print files and satellite imagery. Lossless storage, high bit depths, CMYK support and multiple pages in one file make it indispensable to archivists and printers. The same flexibility makes the files huge and keeps TIFF almost entirely off the web. This article covers TIFF's history from Aldus to Adobe, its tag-based structure, compression options, extensions such as GeoTIFF, common problems and how to convert TIFF files to JPG or PNG.
What is TIFF?
TIFF (Tagged Image File Format) is a tag-based file format designed for storing raster images and exchanging them between programs. The extensions are .tif and .tiff and the MIME type is image/tiff. In the words of the TIFF 6.0 specification, TIFF is not a printer language or page description language; its purpose is to describe and store raster image data.
What sets TIFF apart is that it is not tied to a single compression method or color model. The Library of Congress describes TIFF as a wrapper for different bitstream encodings, which can use different compression schemes and color representations.
History: Aldus, Microsoft and Adobe
- Fall 1986: After a series of meetings with scanner manufacturers and software developers, Aldus Corporation published the first TIFF specification. Because two major drafts came before it, this version is effectively "3.0". The goal was a common format for desktop scanners.
- April 1987: Revision 4.0, mostly minor enhancements.
- October 1988: Revision 5.0, from Aldus and Microsoft, added palette color images and LZW compression.
- 3 June 1992: TIFF Revision 6.0, still the baseline today, was published. It added CMYK, YCbCr and CIE L*a*b* image definitions, tiled images and JPEG compression, and split the specification into "Baseline" and "Extensions".
- 1994: Adobe acquired Aldus and with it the rights to the TIFF specification.
- 1995 and 2002: Two supplements followed as PageMaker and Photoshop technical notes. The 2002 supplement defined Deflate (ZIP) compression and corrected the earlier flawed description of JPEG compression in TIFF.
Technical structure
Header and byte order
Every TIFF file starts with an 8-byte header. The first two bytes give the byte order: II (Intel, little-endian) or MM (Motorola, big-endian). Then come the number 42 and the offset of the first image file directory (IFD). In hex, a TIFF begins with either 49 49 2A 00 or 4D 4D 00 2A.
IFDs and tags
An IFD (Image File Directory) is a list of fields describing the image. Each field is a 12-byte record: the tag number, the data type, the number of values and the value itself or its offset. Core tags include ImageWidth, ImageLength, BitsPerSample, Compression, PhotometricInterpretation, XResolution and YResolution, plus the data location (StripOffsets or TileOffsets). Because readers can skip tags they do not understand, the format is easy to extend; that is both TIFF's strength and the source of its compatibility problems.
Strips, tiles and multi-page files
Pixel data is stored in horizontal strips, or in square tiles introduced with TIFF 6.0. Tiles let software read only the visible part of a very large image, which matters for maps and microscopy. Since each IFD also points to the next one, a single file can hold multiple images (subfiles). Multi-page faxes and scanned documents are stored this way, and TIFF-FX (RFC 3949) defines a TIFF-based format for internet fax.
The file size limit and BigTIFF
According to TIFF 6.0, the largest possible TIFF file is 2^32 bytes, about 4 GB, because offsets are written as 32-bit numbers. BigTIFF, which uses 64-bit offsets, was developed for very large images, but application support remains limited.
Color models, bit depth and transparency
TIFF 6.0 defines bilevel (black and white), grayscale, palette and RGB images as Baseline features. Extensions add CMYK for printing, YCbCr for video and JPEG, and the device-independent CIE L*a*b*. Besides 8 bits per channel, 16-bit (even floating-point) samples are possible; 16-bit TIFF is common in professional photography and scientific imaging. Extra channels (ExtraSamples) can be declared as alpha, so TIFF can carry transparency. Programs such as Photoshop can also write layers into TIFF using their own private tags, but not every program can read those layers.
Compression options
| Method | Loss | Best for |
|---|---|---|
| Uncompressed (1) | Lossless | Widest compatibility, largest files |
| CCITT Group 3 / Group 4 | Lossless | Black-and-white scans and fax |
| PackBits (32773) | Lossless | Simple run-length encoding, flat areas |
| LZW (5) | Lossless | General purpose; moderate gains on photos and graphics |
| Deflate / ZIP (8) | Lossless | Usually compresses slightly better than LZW |
| JPEG | Lossy | Photos; smaller files at the cost of quality |
In 1992 LZW was moved from Baseline into the Extensions part because of licensing issues. According to the Library of Congress, the relevant patent expired in 2003 in the US and in 2004 in Europe and Japan, so LZW is free to use today.
Typical uses
- Scanning and digital archives: TIFF is widely used as a master format for scanned images. The Library of Congress reports holding more than 3.5 petabytes of TIFF files in early 2022, and the FADGI guidelines it helps lead use TIFF for master files.
- Print and publishing: CMYK support and lossless storage made TIFF the standard for images sent to print for many years.
- Professional photography: 16-bit masters exported from RAW files are often stored as TIFF. Many camera raw formats are themselves based on the TIFF structure (TIFF/EP, ISO 12234-2).
- Geographic information systems (GeoTIFF): Developed in the early 1990s, GeoTIFF adds coordinate and projection information to TIFF tags. Revision 1.0 was defined in November 1995; today it is the OGC GeoTIFF 1.1 standard and is widely used for satellite and aerial imagery and elevation models.
- Medicine and science: Microscopes, telescopes and lab instruments choose TIFF for its high bit depth and lossless storage.
- Fax: Multi-page, CCITT-compressed black-and-white TIFF is the classic fax format.
Support
Windows Photos, macOS Preview, Photoshop, GIMP, Affinity Photo and GIS software such as QGIS open TIFF. The web is a different story: according to MDN, browsers other than Safari do not display TIFF images natively, so TIFF is not used for web content, although it is common to offer TIFF files as downloads for precise editing or printing.
Strengths and weaknesses
| Strengths | Weaknesses |
|---|---|
| Lossless storage, 16-bit and higher bit depths | Very large files |
| CMYK, Lab and ICC profile support | Not displayed by browsers other than Safari |
| Multi-page files and tiling | The variety of tags and compressions causes compatibility issues |
| Recommended by archives, well documented | 4 GB limit in standard TIFF |
| Extensible: GeoTIFF, TIFF/EP, TIFF-FX | Impractical for e-mail and upload forms |
Common problems and how to fix them
The TIFF file is too big
A single scanned page as TIFF can be tens of megabytes. To share it, converting TIFF to JPG usually brings it down to a few hundred kilobytes. To keep detail losslessly, convert TIFF to PNG; compared with an uncompressed TIFF, the PNG is often much smaller. Keep the archival copy as TIFF; re-saving it with LZW or Deflate compression also saves space without loss.
A program or website will not open the TIFF
Either the program does not support TIFF at all, or the file uses a compression, color model (CMYK, Lab) or bit depth it cannot handle. Converting to JPG or PNG works in both cases.
Only the first page of a multi-page TIFF shows up
Many viewers and converters read only the first IFD. Our TIFF converters also convert only the first page. If you need every page, split the file into single pages first; after converting the pages to JPG you can combine them into one PDF with JPG to PDF.
Colors changed after conversion
CMYK or wide-gamut TIFF files prepared for print are converted to sRGB for screens and the web, and saturated colors in particular can shift slightly. 16-bit files are also reduced to 8 bits per channel in JPG and PNG.
A file larger than 4 GB cannot be saved
You have reached the limit of standard TIFF. Save with a program that supports BigTIFF, or split the image into parts.
Conversion tips
- JPG for sharing and the web: The smallest, most compatible result for photos and color scans.
- PNG for text, line art and editing: Lossless, so sharp edges stay intact.
- Still too large? Reduce the converted file with resize image, or bring it to a target file size with compress image; both tools run in your browser.
- Keep the master: Archive the original of every TIFF you convert to JPG; going from JPG back to TIFF does not bring lost detail back.
Note: because most browsers cannot read TIFF, on our TIFF conversion pages the files are uploaded to our servers over a secure connection, converted there and deleted within 30 minutes at the latest.
Frequently Asked Questions
Is there a difference between TIF and TIFF?
No. Both are extensions for the same format; .tif dates from older systems limited to three-character extensions.
Is TIFF lossless?
Mostly, yes. Uncompressed, LZW, Deflate, PackBits and CCITT-compressed TIFFs are lossless. JPEG-compressed TIFF is lossy.
Why are TIFF files so big?
TIFF usually stores pixels without lossy compression, often at a high bit depth. A JPG of the same picture is much smaller thanks to lossy compression.
Should I send TIFF or PDF to a printer?
TIFF is still widely accepted for single images; for layouts that combine text and images, print shops usually ask for PDF. Check the print provider's requirements before sending.
Does a GeoTIFF open in a normal TIFF viewer?
Yes, the image part opens like any TIFF. Reading the coordinate and projection information requires GIS software such as QGIS, and that information is lost when you convert to JPG or PNG.
