TIFF to GIF Converter

Encoding: the TIFF uses none, LZW, PackBits, Deflate or JPEG, chosen per file; GIF uses lossless LZW over a palette of at most 256 colours, and the download is a GIF with an optimised palette of up to 256 colours per frame, dithered.

Bit depth: 1 to 16 bits per channel, or 32-bit floating point in the TIFF; GIF allows 8 bits per pixel, as indexes into a palette, and the GIF written here has 8 bits per pixel (palette). 16-bit and floating-point TIFFs are reduced to 8 bits per channel.

Colour: RGB, CMYK, Lab, greyscale or palette, often with an ICC profile in the TIFF; GIF supports an indexed palette of up to 256 colours per frame, written here as an indexed palette of up to 256 colours.

Transparency: the TIFF stores it as an extra sample declared in the ExtraSamples tag; the GIF keeps it as on or off per pixel, so soft edges become hard.

Other images: the TIFF can hold several pages, each in its own image file directory; only the main image is converted.

Metadata: the TIFF can carry EXIF, XMP, IPTC and ICC, all stored as tags; GIF can carry comment and application extension blocks, but no EXIF, but nothing is copied across.

TIFF is the professional archive and print format. It can hold multiple pages, high bit depths and lossless data, and is common in scanning, publishing and GIS.

A TIFF begins with 'II' or 'MM' for the byte order and the number 42, then an offset to the first image file directory (IFD): a table of tags giving the size, compression, colour model and the location of the strips or tiles of pixels. Each further page is another IFD.

TIFF files usually come from scanners, print and publishing workflows, photo archives and tethered camera capture.

GIF is the classic animated image format. It is limited to 256 colours per frame and 1-bit transparency, so photos look grainy and files are large, but it plays everywhere.

A GIF starts with 'GIF89a' (or the older 87a), a logical screen descriptor and an optional global colour table, then image blocks, each preceded by a graphic control extension that sets its delay and transparent colour.

GIF is the better choice for short animations and reactions that must play everywhere, while TIFF suits printing, scanning and archival masters.

GIF strengths: Animation that works everywhere; Simple, universally supported; Good for small flat graphics. Drawbacks to weigh: Only 256 colours per frame; Hard-edged transparency only; Large files for photos or long clips.