Building a World Map with only 500 bytes

# Building a World Map with only 500 bytes Source: [https://simonwillison.net/2026/Jul/4/building-a-world-map-with-only-500-bytes/](https://simonwillison.net/2026/Jul/4/building-a-world-map-with-only-500-bytes/) 4th July 2026 \- Link Blog **[Building a World Map with only 500 bytes](https://www.experimentlog.com/blog/building-a-world-map-with-only-500-bytes)**\([via](https://news.ycombinator.com/item?id=48747762)\) Iwo Kadziela \(assisted by Codex\) figured out a way to generate a credible ASCII world map using 445 bytes of data:  The key trick is to use deflate compression, which is then wired together using this neat snippet of JavaScript\. I didn't know you could use`fetch\(\)`with`data:`URIs like this: ``` fetch('data:;base64,1ZpLsgIxCEXnrM...==').then( r => r.body.pipeThrough(new DecompressionStream('deflate-raw')) ).then( s => new Response(s).text() ).then( t => b.innerHTML = '<pre style=font-size:.65vw>' + t ) ```