I have not used Claude Code in a couple months. THEY HAVEN’T FIXED THIS YET?
I’m starting to think that the reason why anthropic doesn’t open source Claude code isn’t due to competitive reasons, it’s because they don’t want people to see what a mess their code base is.
Maybe they bought Bun to increase the rate of flickering so that the text looks solid again
I wouldn't be able to ship this to anyone without fixing it. Sending 5,000 lines of text to a terminal just to clear them all immediately, and in a loop... i'd be so embarrassed. Apps that clear scrollback have their uses, but you don't spam the terminal with unusable garbage.
And we solved this problem over 30 years ago? Ncurses was made for this. The buffer is kept in memory, you hit page-up and it renders the previous page, page-down and it renders the next page, let it roll and it renders each successive page as a stream, or just the last page, etc.
Many users do like to use scrollback to copy large passages of text, which becomes difficult and cumbersome if they have to use page-up page-down to get at the other parts of it.
I would love to use this but it breaks Ghostty's native scrollback (two-finger scroll), which I want more than I want to solve the flickering. The PTY proxy intercepts the output stream so Ghostty can't access its internal scrollback buffer anymore.
How does Ghostty break scroll? I've never noticed this and I just tested, seems to work fine. My problem is the lack of a scrollbar but I know they are working on that.
I guess it's not hard to use AI to improve your productivity by 10x when your code is written by 0.1x devs. It's embarrassing an OSS fixed their problem before they did after all that money they raised
I don't know if this is my problem but formatting has been completely broken recently. It feels ... vibe coded. I wish they had not blocked opencode :(
One feature I'd love is a toggle to lock the input to the bottom of the terminal. It's a big inconvenience to have to scroll up and down between the chat and the input when responding to changes.
Hi! I work on TUI rendering for Claude Code. I know this has been a long-standing frustration — it's taken longer than any of us wanted.
The good news: we shipped our differential renderer to everyone today. We rewrote our rendering system from scratch[1] and only ~1/3 of sessions see at least a flicker. Very, very few sessions see flickers in rapid succession which was so annoying before. Those numbers will keep dropping as people update.
We've also been working upstream to add synchronized output / DEC mode 2026 support to environments where CC runs and have had patches accepted to VSCode's terminal[2] and tmux[3]. Synchronized output totally eliminates flickering. As always, I recommend using Ghostty which has 2026 support and zero flicker.
i’ve noticed the issue with tmux more than with specific terminals.
basically, the rapid replay of the entire conversation history (the CC bug) somehow interacts destructively with something in tmux, causing it to be 10 times worse. The “flicker” becomes a multi-second delay while I wait twiddling my thumbs…
i’ve seen this in every terminal, including ghostty… as nice as ghostty is, expecting everyone to use it is kinda meh (at least support Wezterm too, lol)
While I have you on the line, I'm also experiencing tons of API request timeouts using Claude Code's own TUI client (on the $200/mo plan!!) and I don't know how to mitigate that, and it is frustrating
I'm not even using it particularly hard. Usually only one agent is running with possibly one sub-agent on occasion. Which is confusing because I've heard of people running ten at once and only then running into this issue...
Possibly related, I DID only upgrade to the $200 tier a few days ago... might there be a now-stale API rate limit in place?? Or maybe it's the long-running multi-compacted context that's the problem?
My account is tied to lumbergh-at-gmail-dot-com
I'm a dev so of course, happy to help run it down from my end
This tool is amazing btw. I'm currently working on a never-existed-before app that would have been impossible before AI... And it's going quite well
Codex is so much more responsive for me no matter how long the session is running. Claude just starts stuttering badly when the session is running for sometime.
Sometimes Claude Code scrolls up far away, and I struggle to scroll it down again. And I have to restart the terminal and Claude Code for it to behave well again. But I don't know if this is the flickering issue, or if it's due to a bug in Windows, Alacritty, Zsh or something else.
I was having this issue with Claude code, and even worse with Gemini, while using the VSCode terminal. I switched to Ghostty and I don't have any flickering or weird scrolling issues at all anymore.
34 comments
[ 2.4 ms ] story [ 69.2 ms ] threadI’m starting to think that the reason why anthropic doesn’t open source Claude code isn’t due to competitive reasons, it’s because they don’t want people to see what a mess their code base is.
Maybe they bought Bun to increase the rate of flickering so that the text looks solid again
And we solved this problem over 30 years ago? Ncurses was made for this. The buffer is kept in memory, you hit page-up and it renders the previous page, page-down and it renders the next page, let it roll and it renders each successive page as a stream, or just the last page, etc.
Anthropic: Please fix this ASAP
We've rewritten Claude Code's terminal rendering to reduce flickering by 85% - https://news.ycombinator.com/item?id=46312507 - Dec 2025 (3 comments)
The good news: we shipped our differential renderer to everyone today. We rewrote our rendering system from scratch[1] and only ~1/3 of sessions see at least a flicker. Very, very few sessions see flickers in rapid succession which was so annoying before. Those numbers will keep dropping as people update.
We've also been working upstream to add synchronized output / DEC mode 2026 support to environments where CC runs and have had patches accepted to VSCode's terminal[2] and tmux[3]. Synchronized output totally eliminates flickering. As always, I recommend using Ghostty which has 2026 support and zero flicker.
Happy to answer questions!
[1]: https://github.com/anthropics/claude-code/issues/769#issueco...
[2]: https://github.com/xtermjs/xterm.js/pull/5453
[3]: https://github.com/tmux/tmux/pull/4744
basically, the rapid replay of the entire conversation history (the CC bug) somehow interacts destructively with something in tmux, causing it to be 10 times worse. The “flicker” becomes a multi-second delay while I wait twiddling my thumbs…
i’ve seen this in every terminal, including ghostty… as nice as ghostty is, expecting everyone to use it is kinda meh (at least support Wezterm too, lol)
I'm not even using it particularly hard. Usually only one agent is running with possibly one sub-agent on occasion. Which is confusing because I've heard of people running ten at once and only then running into this issue...
Possibly related, I DID only upgrade to the $200 tier a few days ago... might there be a now-stale API rate limit in place?? Or maybe it's the long-running multi-compacted context that's the problem?
My account is tied to lumbergh-at-gmail-dot-com
I'm a dev so of course, happy to help run it down from my end
This tool is amazing btw. I'm currently working on a never-existed-before app that would have been impossible before AI... And it's going quite well
I had to use Codex today cause claude kept scrolling up every time the window lost focus. It was so annoying. macOS iTerm
Sounds like only is a bit misplaced. IMHO such bugs that take forever to fix make Anthropic seem very unprofessional.
Sometimes Claude Code scrolls up far away, and I struggle to scroll it down again. And I have to restart the terminal and Claude Code for it to behave well again. But I don't know if this is the flickering issue, or if it's due to a bug in Windows, Alacritty, Zsh or something else.