Why PNG Stands for “I’m Not GIF”: The Story Behind the Format

PNG name origin

PNG stands for Portable Network Graphics, but the format was originally called PING, a recursive acronym meaning “PING Is Not GIF”. The name was coined by Oliver Fromme.

Why PNG was created

GIF was introduced in 1987 by CompuServe engineer Bob Berry and used the LZW compression algorithm. LZW was patented by Terry Welch in 1983 and later owned by Unisys. The patent was largely ignored at first, allowing GIF to become the de‑facto image format for the early web.

In December 1994 Unisys announced that developers would have to pay royalties for using LZW‑based GIF software. The announcement coincided with the Christmas holidays, so it received little immediate attention, but after the holidays the comp.graphics Usenet newsgroup erupted with criticism.

Community response and design decisions

On 4 January 1995 developer Thomas Boutell posted a call to create a new format that avoided patent fees. The same day contributors suggested replacing LZW with the patent‑free DEFLATE algorithm (the same algorithm used by ZIP and gzip) and adding pre‑compression filtering to improve compression efficiency. Oliver Fromme gave the effort the name “PING Is Not GIF”.

Within about a month the PNG specification iterated through seven drafts and was essentially finalized by early February 1995. The W3C officially recommended PNG in October 1996, and browsers subsequently added support.

Technical characteristics

Supports up to 16 million colors (24‑bit), whereas GIF is limited to 256 colors.

Provides an alpha channel for variable‑opacity transparency, which GIF lacks.

Uses DEFLATE compression; after filtering, PNG’s compression ratio is comparable to or better than GIF’s.

Comparison illustration

Patent expiration and market outcome

Unisys’s LZW patent expired in 2003, freeing GIF from royalty obligations. By that time PNG had already become the dominant static‑image format, while GIF persisted mainly for animated images and memes.

Broader pattern

The PNG story illustrates a recurring pattern where communities create open, patent‑free alternatives to patented standards: Ogg Vorbis for MP3, AV1 for H.264/H.265, MariaDB for MySQL, and Linux for AT&T’s Unix. The motivating principle is “you charge us, we rewrite it.”

Code example

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