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0 pointskrystofbe4mo ago0 comments

I did some debugging on this today. The results are... sobering.

Memory comparison of AI coding CLIs (single session, idle):

  | Tool        | Footprint | Peak   | Language      |
  |-------------|-----------|--------|---------------|
  | Codex       | 15 MB     | 15 MB  | Rust          |
  | OpenCode    | 130 MB    | 130 MB | Go            |
  | Claude Code | 360 MB    | 746 MB | Node.js/React |

That's a 24x to 50x difference for tools that do the same thing: send text to an API.

vmmap shows Claude Code reserves 32.8 GB virtual memory just for the V8 heap, has 45% malloc fragmentation, and a peak footprint of 746 MB that never gets released, classic leak pattern.

On my 16 GB Mac, a "normal" workload (2 Claude sessions + browser + terminal) pushes me into 9.5 GB swap within hours. My laptop genuinely runs slower with Claude Code than when I'm running local LLMs.

I get that shipping fast matters, but building a CLI with React and a full Node.js runtime is an architectural choice with consequences. Codex proves this can be done in 15 MB. Every Claude Code session costs me 360+ MB, and with MCP servers spawning per session, it multiplies fast.

| Tool | Footprint | Peak | Language | |-------------|-----------|--------|---------------| | Codex | 15 MB | 15 MB | Rust | | OpenCode | 130 MB | 130 MB | Go | | Claude Code | 360 MB | 746 MB | Node.js/React |

0 comments

7 comments · 4 top-level

atonse4mo ago· 3 in thread

Jarred Sumner (bun creator, bun was recently acquired by Anthropic) has been working exclusively on bringing down memory leaks and improving performance in CC the last couple weeks. He's been tweeting his progress.

This is just regular tech debt that happens from building something to $1bn in revenue as fast as you possibly can, optimize later.

They're optimizing now. I'm sure they'll have it under control in no time.

CC is an incredible product (so is codex but I use CC more). Yes, lately it's gotten bloated, but the value it provides makes it bearable until they fix it in short time.

FuckButtons4mo ago

Bold of you to assume this is a quick fix. How many software projects have you worked on that went from a buggy poorly optimized mess into a streamlined efficient system? I can think of exactly 0 from personal experience, all the ones I’ve worked on that were performant at the end had that in mind from their inception.

bdangubic4mo ago

if I had a dollar for each time I heard “until they fix it in short time” I’d have Elon money

tatjam4mo ago

Claude, fix the memory leaks, or you'll go to jail!

badlogic4mo ago

OpenCode is not written in Go. It's TS on Bun, with OpenTUI underneath which is written in Zig.

Weryj4mo ago

I believe they use https://bun.com/ Not Node.js

slopusila4mo ago

why do you care about uncommitted virtual memory? that's practically infinite

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