Claude Sonnet 5.5 vs Claude Sonnet 5: API price, context and cost per task
Claude Sonnet 5.5 arrived on 28 September 2026 as a direct upgrade to Sonnet 5.
Today both list at $2 per million input tokens and $10 per million output tokens.
Data updated 2026-11-11 - source: public OpenRouter model list, refreshed daily. Prices in USD, excluding VAT.
Specs and prices side by side
| Claude Sonnet 5.5 | Claude Sonnet 5 | |
|---|---|---|
| Vendor | Anthropic | Anthropic |
| Input, per 1M tokens | $2 | $2 |
| Output, per 1M tokens | $10 | $10 |
| Cached input, per 1M | $0.1 | $0.2 |
| Batch (input / output) | $1 / $5 | $1 / $5 |
| Context window | 1,000,000 | 1,000,000 |
| Max output | 128,000 | 128,000 |
| Input types | text, images, files | text, images, files |
| Reasoning | Yes | Yes |
| Tool calling | Yes | Yes |
| On OpenRouter since | 28 Sep 2026 | 30 Jun 2026 |
Highlighted: the cheaper price or the larger limit. "Not published" means the figure is not in the public model listing yet.
What a month of work costs
Four typical workloads at today's list prices. Reasoning models also bill their thinking as output tokens, so treat output-heavy numbers as a floor.
| Workload | Claude Sonnet 5.5 | Claude Sonnet 5 | Difference |
|---|---|---|---|
| Support chatbot10,000 conversations a month, about 1,500 input and 400 output tokens each | $70 | $70 | same |
| Coding agent300 tasks a month, about 80,000 input tokens (code context re-read across steps) and 8,000 output tokens each | $72 | $72 | same |
| Coding agent with caching70% of input served from the prompt cache | $40.08 | $41.76 | |
| Long-document analysis1,000 documents a month, about 50,000 tokens in and a 1,500-token summary out | $115 | $115 | same |
| Content drafting600 articles a month, about 3,000 tokens of brief in and 2,500 tokens of draft out | $18.60 | $18.60 | same |
Price stability over the last 30 days
- Claude Sonnet 5.5: no change in the last 30 days.
- Claude Sonnet 5: no change in the last 30 days.
What the vendors and benchmarks say
Claude Sonnet 5.5
"Claude Sonnet 5.5 is Anthropic's Sonnet-class model for well-scoped everyday work, succeeding Claude Sonnet 5 as a direct upgrade."model card on OpenRouter
- Listed on OpenRouter on 28 September 2026 as the direct successor to Claude Sonnet 5. Source: OpenRouter
Claude Sonnet 5
"Sonnet 5 is Anthropic's most capable Sonnet-class model, with frontier performance across coding, agents, and professional work."model card on OpenRouter
Which one to pick
The model card positions Sonnet 5.5 as the direct successor for everyday work such as building features and fixing bugs. At launch it kept Sonnet 5's list rates and context window, so the upgrade is a quality decision rather than a budget one: re-run your prompts, watch output length (on reasoning models it drives the bill) and switch.
Cheaper models with a similar context window
Models from our comparison set that cost less than both on a blended basis and support tool calling. They are not equivalent in quality - test before switching.
- Qwen3.8 Max (Alibaba (Qwen)): $2 / $6 per million tokens, 1M context
- Gemini 3.8 Flash (Google): $0.825 / $4.13 per million tokens, 1.05M context
- DeepSeek V4 Pro (DeepSeek): $0.955 / $1.91 per million tokens, 1.05M context
Related reading
How we calculate
Prices are the public per-token list rates from OpenRouter's model list, which match the vendors' own API prices for first-party models and show the current routed price for open-weight models served by several hosts. Monthly costs multiply those rates by the token volumes in each workload; caching assumes the stated share of input is billed at the cached-input rate. Benchmarks and claims are quoted from the named sources, mostly the vendors themselves - treat them as a guide and test on your own tasks. See also the AI cost calculator and all tracked model prices.
Frequently asked questions
Which is cheaper, Claude Sonnet 5.5 or Claude Sonnet 5?
As of 11 Nov 2026, Claude Sonnet 5.5 costs $2 per million input tokens and $10 per million output tokens; Claude Sonnet 5 costs $2 and $10. Claude Sonnet 5.5 is cheaper in 0 of the 4 monthly workloads we price on this page. The real bill also depends on how many reasoning tokens each model writes.
Which has the larger context window?
Claude Sonnet 5.5 reads up to 1,000,000 tokens and can write up to 128,000; Claude Sonnet 5 reads up to 1,000,000 and writes up to 128,000.
How much does a support chatbot cost on each model?
For 10,000 conversations a month (about 15 million input and 4 million output tokens) you would pay about $70 on Claude Sonnet 5.5 and $70 on Claude Sonnet 5 at list prices, before any caching or batch discounts.
Do they offer prompt caching or batch discounts?
Claude Sonnet 5.5 lists cached input at $0.1 per million and a batch rate of $1 / $5. Claude Sonnet 5 lists cached input at $0.2 per million and a batch rate of $1 / $5. Caching matters most for agents and chatbots that resend the same context on every turn.
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