signalHacker News Best2026-09-29
Sonnet 5.5
Claude Sonnet 5.5 is a faster and cheaper upgrade to Sonnet 5, with 30%+ faster output and up to 30% lower cost per task. It scores 70.6% on Terminal-Bench 4.0, far above Sonnet 5's 10.3%, and nearly matches Opus 5.5 on GDPval-AA. Priced at $2 per million input tokens and $10 per million output, it excels at everyday coding and knowledge work.
- for who
- Developers and knowledge workers handling everyday tasks, bug fixes, and document creation.
- why now
- New Claude Sonnet 5.5 is now available, faster and cheaper for coding.
- what changes
- They can get faster, cheaper results on routine work, with performance approaching Opus 5.5 at lower effort settings.
- to do
- Use Sonnet 5.5 for well-scoped coding and document tasks to cut costs and speed up iteration.
key points
- Sonnet 5.5 runs 30% faster and costs up to 30% less per task than Sonnet 5
- Scores 70.6% on Terminal-Bench 4.0, versus 10.3% for Sonnet 5
- First Sonnet model to beat Pokémon Red from screenshots alone
#claude sonnet 5.5#model performance comparison#low cost high speed#agentic coding
score
score 9 out of 10. 0-10: how dense the facts are, multiplied by how much you can do with them after reading. 8+ means the topic's evidence bar is met: benchmarks and availability for a new model, amount and investors for a funding round, revenue figures for a solo-money story. Below 5 an item does not enter the digest. A press release scores 3 or less, a reprint loses 2, anything older than 14 days loses 1, a headline that misleads loses 3.
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