What's happening
Anthropic's published pricing lists Claude Sonnet 5 at $2 per million input / $10 per million output tokens as introductory pricing through August 31, 2026. From September 1, 2026, standard pricing takes effect: $3 / $15 per MTok — a 50% increase on both sides. (Source: Anthropic's pricing page, verified 2026-09-07.)
What it does to a real workload
A workload of 50M input + 10M output tokens/month on Sonnet 5:
| Through Aug 31 | From Sept 1 | |
|---|---|---|
| Input | $100 | $150 |
| Output | $100 | $150 |
| Monthly | $200 | $300 |
Your options
- Stay and budget it. $3/$15 matches Sonnet 4.6/4.5 pricing — the intro rate was the anomaly.
- Batch what can wait. The Batch API halves both sides ($1.50/$7.50 post-increase).
- Cache what repeats. Cache reads run 0.1× input; long shared prefixes blunt most of the increase.
- Right-size per task. Haiku 4.5 at $1/$5 handles plenty of production traffic; compare on the calculator.
Where Sonnet 5 sits in the table after the increase
Of the 30 active models in our verified table, 12 are cheaper than Sonnet 5 on combined input+output rate at the introductory $12 per MTok-pair; from 2026-09-01 at $18 that becomes 16. The full ranking is on the pricing table. Cache reads are listed at $0.20 per MTok today — 0.1× the input rate; Anthropic has not published a post-increase cache rate, so if the ratio holds expect $0.30 (unconfirmed — we re-verify each refresh cycle and will update this page when the source page states it).
Remember the tokenizer footnote: Sonnet 5 tokenizes ~30% heavier than pre-4.7 Claude models, so cross-family comparisons need real-payload benchmarks, not just rate cards.