How I Fixed ChatGPT’s UI Performance Bottlenecks: A Deep Dive into DOM Management

We’ve all been there. You’re 50 messages deep into a complex coding session with ChatGPT, and suddenly, the interface starts to crawl. Scrolling feels slow, and your fans start spinning like crazy.

As a Software Developer myself, I couldn't just ignore the lag. I had to figure out why it was happening — and then I had to fix it.

The Problem: The "bloated" DOM
The culprit behind ChatGPT’s slowdown isn't usually the AI itself; it's the Document Object Model (DOM) in your browser, and how OpenAI decided to manage it.

ChatGPT’s web interface has one major flaw: long conversations create a massive DOM tree that is never cleared. Every message, every code block, and every formatting tag adds weight, and none of it ever gets removed. When you reach a certain threshold, the browser's rendering engine has to work overtime just to handle simple re-paints and reflows.

The Technical Bottleneck: Every time a new token is "streamed" into a long conversation, the browser might be recalculating styles for thousands of elements.

The Solution: Pruning and Optimization
I decided to build Speed Booster for ChatGPT to tackle this problem. It's a small Chrome / Firefox extension that completely fixes the browser lag problem with ChatGPT.

DOM Pruning
The extension allows you to select how many older messages to keep visible, and hides older messages - making the rendering speed of the page as fast as a new conversation again, even in chats with 500+ messages. Older messages can be easily viewed again by pressing a 'show older messages' button.

Learnings
What started out as a simple fix for something I found annoying has reached 50.000+ users so far, and the most rewarding part has been the feedback.

Many people have let me know how much this extension has helped them make ChatGPT usable again. One user recently pointed out that while the speed is great, they missed being able to search through "pruned" text easily. This is the beauty of indie development: you get to iterate on real-world problems and many people are willing to point out points for improvement. My next sprint is focused exactly on that: Searchable History vs. Performance.

Try it out for yourself, and let me know what you think!
If you struggle with ChatGPT lag, have tips or want to talk about DOM optimization strategies, I'd love to hear from you in the comments.

If you want to know how to speed up ChatGPT, you can check out the extension here:

Speed Booster for ChatGPT - Chrome

Speed Booster for ChatGPT - Firefox

I would love to hear if this was a problem for you, and if my extension fixes it for you - let me know! ;-)