Head to head · prices checked 15 October 2026

Claude Sonnet 5.5 vs Claude Sonnet 5

There is no quality verdict yet: the AIGROW small-business benchmark has not run Claude Sonnet 5.5. On price they match: both cost $2 in and $10 out per million tokens.

US dollars, standard rate, shortest context band. Price only: the benchmark has not run both.

1,000 support replies
Eventhe two cost the same on this job
Claude Sonnet 5.5
$10.00
Claude Sonnet 5
$10.00
Claude Sonnet 5.5, per M tokens
$2 / $10
Claude Sonnet 5, per M tokens
$2 / $10

3,000 tokens in and 400 out each, at list price.

Anthropic's new Sonnet against the one it replaces, at the same list price with a cheaper cache. 1,000 support replies cost $10.00 on either. Claude Sonnet 5.5 was released on 28 Sep 2026, Claude Sonnet 5 was released on 30 Jun 2026.

What each one costs

The API price per million tokens and the cheapest app plan with each model, from the makers’ own pages. Each name opens that model’s full price page.

Claude Sonnet 5.5
On the Anthropic API, Claude Sonnet 5.5 costs $2 per million input tokens and $10 per million output tokens. In Claude, it comes with the free plan, and the cheapest paid plan with it is Pro at $20/mo. Plan prices read 20 October 2026. AIGROW API credit runs Claude Sonnet 5.5 at $1.50 / $7.50 per million input / output tokens, 25% below list price. See API credit
Claude Sonnet 5
On the Anthropic API, Claude Sonnet 5 costs $2 per million input tokens and $10 per million output tokens.

Side by side

Each maker’s published rate for its standard tier. Cached input is what a repeated prompt prefix costs once the provider has stored it.

Claude Sonnet 5.5 and Claude Sonnet 5: list prices and specifications
FactClaude Sonnet 5.5Claude Sonnet 5
MakerAnthropicAnthropic
TierWorkhorsesWorkhorses
Input, per M tokens$2.00$2.00
Output, per M tokens$10.00$10.00
Cached input$0.10$0.20
Context window1M1M
Released28 Sep 202630 Jun 2026
WeightsClosed weightsClosed weights

What a job costs on each

1,000 runs of each job at the two list prices. The gap moves from job to job because the models price input, output and cached context differently.

Cost of 1,000 runs of three jobs on Claude Sonnet 5.5 and Claude Sonnet 5
JobClaude Sonnet 5.5Claude Sonnet 5Cheaper
Support reply3,000 in, 400 out.$10.00$10.00Even
Document summary25,000 in, 1,000 out.$60.00$60.00Even
Agent task80,000 in (70,000 cached), 3,000 out.$57.00$64.00Claude Sonnet 5.5, 11% less

The token counts are ours, chosen to look like real work; the prices are the makers’. A model with no published cache price bills the agent task’s repeated context at its full input rate.

The small print

What each base rate leaves out, from the makers’ own pages: surcharges, discounts, promotions and cache pricing.

Claude Sonnet 5.5
Cache read is 0.05x input on this model ($0.10). Cache write $2.50 (5 min) or $4 (1 h). Batch API 50% off. US-only inference bills 1.1x. Full context window billed at standard rates. Max output 128K. Anthropic’s pricing page
Claude Sonnet 5
Legacy model, still available; the current Sonnet is Claude Sonnet 5.5. The introductory $2 / $10 price became the standard price; the planned rise to $3 / $15 was cancelled. Cache write $2.50 (5 min) or $4 (1 h). Batch API 50% off. US-only inference bills 1.1x. Full context window billed at standard rates. Anthropic’s pricing page

Run Claude Sonnet 5.5 up to 25% below list price

AIGROW API credit covers Claude Sonnet 5.5 at published rates never above the list prices here, and $25 buys $100 of credit.

Prices checked 15 October 2026