Engineering case study · Browser extension
Smooth GPT: reducing the work behind a long chat
Long conversations can leave a browser managing many messages and complex code blocks at once. Smooth GPT is a Chrome extension that applies several targeted techniques to that page. This is how those techniques fit together.
The challenge
A long chat can accumulate message elements even when most are far outside the viewport. Code editors add more structure. The extension needed to reduce rendering work while keeping the conversation usable and giving users control over the more aggressive options.
Four layers of the approach
Trim older API messages
An optional API response transform removes older messages before React renders them. This addresses the amount of content entering the page, rather than only hiding it afterward.
Skip offscreen layout and paint
CSS content-visibility lets the browser defer rendering work for content outside the visible area while leaving that content in the document.
Deflate offscreen code blocks
When a CodeMirror block is offscreen, Smooth GPT can replace its heavy editor structure with plain text and restore the editor as it comes back into view.
Offer optional DOM pruning
For users who need a stronger intervention, an optional mode detaches far-away message nodes. It is kept separate from the lighter techniques because it changes the live page more substantially.
What users can inspect
The extension popup exposes controls and counters for messages, DOM nodes, and deflated blocks. Users can turn individual strategies on or off and compare how their own conversation behaves.
What this does not prove
The techniques target rendering and DOM overhead; their effect depends on conversation length, content, browser, and settings. We have not published a controlled cross-device timing benchmark, so we do not claim a universal speedup here.