pxpipe hides text in PNGs to cut token costs by up to 70%

The open-source tool pxpipe converts large text chunks in Claude Code requests into dense PNG images to save on token usage. The trick exploits Anthropic’s pricing: text costs roughly one token per character, while images cost a fixed amount based on pixel dimensions.

pxpipe runs as a local proxy. It intercepts requests and renders static content like system prompts, documentation, and chat history into images. For example, a 48,000-character prompt costs about 25,000 tokens as text, but only 2,700 tokens as a PNG.

Developer Steven Chong reports average savings of 59% to 70%. In a Fable 5 demo, session costs dropped from $42.21 to $6.06. The trade-off is that the method is lossy. Exact strings like hashes can be misread, and processing is slower due to the vision encoder.