Claude Opus 4.5: what 322 developers actually say.
322 Hacker News opinions from 259 developers, Nov 2025 – Nov 2026. 254 come from people who say they use it. Here is what they praise, what they complain about, and who switched.
The case for Claude Opus 4.5, in one paragraph.
Claude Opus 4.5 earns 78% approval across 322 opinions. Developers praise its code quality. In the last 90 days it sits at 90%.
Pick it if you
- Want strong code quality, at 120 positive mentions against 28 negative
- Want an agent that keeps working on its own, at 30 positive autonomy mentions against 4
- Care about speed, which drew 15 positive mentions and no negative ones
Look elsewhere if you
- Need steady reliability, which sits near even at 18 positive and 17 negative mentions
- Run growing projects where it gets stuck and claims fixes work
- Need strict instruction following, with one user estimating CLAUDE.md compliance near 70%
Where it wins and loses.
Mentions across 322 opinions. Bars are counts, not votes; a tool can be both praised and criticized on the same topic.
View data table
| Topic | Praise | Complaints | Mentions |
|---|---|---|---|
| Code quality | 120 | 28 | 148 |
| Autonomy | 30 | 4 | 34 |
| Large codebases | 17 | 2 | 19 |
| Speed | 15 | 0 | 15 |
| Cost & pricing | 10 | 2 | 12 |
| Reliability | 18 | 17 | 35 |
How opinion has moved.
Monthly approval, Nov 2025 – Sep 2026. Bars show opinion volume; low-volume months are still included but faded.
View data table
| Month | Approval | Opinions |
|---|---|---|
| Nov 2025 | 50% | 6 |
| Dec 2025 | 84% | 74 |
| Jan 2026 | 69% | 129 |
| Feb 2026 | 76% | 41 |
| Mar 2026 | 78% | 20 |
| Apr 2026 | 93% | 14 |
| May 2026 | 100% | 7 |
| Jun 2026 | 100% | 8 |
| Jul 2026 | 96% | 13 |
| Aug 2026 | 90% | 5 |
| Sep 2026 | 100% | 3 |
What developers say.
Summaries are paraphrased. Each links to the original Hacker News comment.
Praise
4 selectedOpus 4.5 was a big productivity boost, though later frontier models still need babysitting and make mistakes.
Recalls README files generated by Opus 4.5 as clear and concise.
Opus 4.5 was sincerely life-changing when it came out.
Old Opus 4.5 surprisingly worked the first time with their site-description approach.
Complaints
4 selectedOpus 4.5 over-engineers trivial frontend code with custom DOM events.
Opus 4.5 failed three times on a simple asyncio Redis sample, all at the import line.
Opus 4.5 kept drifting on low-level reentrancy constraints, so they moved that code out and wrote it themselves.
Opus 4.5 wrote messy, hacky code with dead paths, and hand-coding would have been faster.
Questions developers ask.
Is Claude Opus 4.5 worth it?
Is Claude Opus 4.5 better than GPT-5.2?
Is Claude Opus 4.5 good for large codebases?
The data behind this page.
Developers give Claude Opus 4.5 an approval score of 78 across 322 opinions from 259 authors, and 254 opinions come from firsthand use. Code quality drives that score, with 120 positive mentions against 28 negative. Approval over the last 90 days is 90, but those months hold small samples, so treat the rise as a weak signal. The loudest period was January 2026, with 129 opinions at 69 approval.
Every number comes from public Hacker News comments collected through the HN Search API. A language model tagged each comment for sentiment, first-hand use, topic and switches; a human spot-checks samples. No vendor can pay for placement.
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