Developer open-sources zero-dependency incremental streaming Markdown renderer for AI chat

On November 11, 2026, a developer posted in Reddit's LocalLLaMA community about open-sourcing a streaming Markdown renderer built for AI chat interfaces. The developer described repeatedly running into a bottleneck while building chat UIs for agents: react-markdown, the library commonly used to render Markdown in the browser, re-parses the entire reply on every token it receives. For long answers that makes rendering noticeably slower, and until a token closes an unfinished span, the raw characters stay visible on screen — for example ** and half-typed [links](htt. Instead of waiting for the closing token, the author wrote a custom renderer that parses incrementally as the reply streams in and repairs syntax that is still unfinished. The component is used as <Markdown streaming={!

done}>{text}</Markdown>, and the project is described as zero-dependency. In the post, the author reports that on a reply of 100k characters it takes 0.25 s of main-thread time in total, compared with the repeated full re-parsing behavior of react-markdown that motivated the project in the first place. The announcement exists so far only as this single post, and the material does not name the renderer, point to a repository, or provide independent verification of the performance claim.