LLM prices / Anthropic / Claude Sonnet 4.5
Anthropic API · prices checked Oct 23, 2026
Claude Sonnet 4.5 API pricing
Short answerClaude Sonnet 4.5 costs $3 per 1M input tokens and $15 per 1M output tokens on the Anthropic API (standard price, checked Oct 23, 2026). A typical chatbot reply (1,500 tokens in, 400 out) costs $0.01, so 1,000 replies a day is about $315 a month and 1M replies is $10,500. Anthropic's own model page marks it deprecated, so it is left out of our picks.
Deprecated. Anthropic lists Claude Sonnet 4.5 as deprecated on its model page. Prices stay here for old bills and migrations. The cheapest current Anthropic model for a chatbot reply is Claude Haiku 5.5.
Best for
- Long repeated prompts (agents, RAG with a fixed prefix): cached input bills at 10% of the normal input price.
- Bulk jobs that can wait: the batch API bills input at 50% of the standard price.
- Reading more than text: takes image input.
Skip if
- You are starting something new: Anthropic marks it deprecated. The cheapest current Anthropic model for a chatbot reply is Claude Haiku 5.5.
- Cost is your constraint: 19 current models answer a chatbot reply for less; the cheapest is Claude Haiku 5.5 at $0.35 per 1,000.
Rules: Best for = cheapest quarter of current models for a chatbot reply, top 3 on one of our 8 jobs, cache reads at 15% or less of input, batch at 60% or less, 1M+ context, non-text inputs. Skip if = not current on the provider's page, priciest quarter, text only, no cache or batch price, a long-prompt surcharge, preview, under 200K context, no tool calling. Price and spec facts only; we don't score answer quality.
What your volume costs
Pick a job and a monthly volume. Same prices as everything on this page; caching and batch applied where they make it cheaper.
Cost per task, 8 jobs
Per 1,000 requests and per month at a typical volume, billed the cheapest way the price list allows. The rank is among current models that fit the job.
| Job (links to the cheapest model for it) | Per 1,000 | A month | Rank among fits |
|---|---|---|---|
| Chatbota 1,500-token prompt (system prompt plus the conversation so far) and a 400-token reply | $10.50standard price | $315at 30,000 a month | does not fit |
| RAG (answer from your docs)6,000 tokens of retrieved passages plus the question, and a 500-token answer | $25.50standard price | $765at 30,000 a month | does not fit |
| Coding agent40,000 tokens of repo context and history, 30,000 of them repeated from the last step and billed at the cache-read price, 2,000 tokens out, tool calling required | $69.00with the repeated 30,000 tokens billed at the cache-read price | $207at 3,000 a month | does not fit |
| Tool-using agent12,000 tokens of instructions, tool definitions and history, 10,000 of them repeated from the last step and cached, 600 tokens out, tool calling required | $18.00with the repeated 10,000 tokens billed at the cache-read price | $180at 10,000 a month | does not fit |
| Vision (read an image)one image counted as 1,000 input tokens plus a 300-token question, and a 300-token answer. Providers count image tokens differently, so treat vision costs as a rough guide | $8.40standard price | $84.00at 10,000 a month | does not fit |
| Translationa 1,000-token passage in and about 1,100 tokens out (translations run a little longer than the source) | $19.50standard price | $195at 10,000 a month | does not fit |
| Batch extraction2,000 tokens per record in and 300 tokens of JSON out, through the batch API where there is one (results within 24 hours) | $5.25through the batch API | $525at 100,000 a month | does not fit |
| Summarize long documentsa 20,000-token document in and an 800-token summary out | $72.00standard price | $72.00at 1,000 a month | does not fit |
Cheaper and pricier alternatives
The current models just below and just above Claude Sonnet 4.5 on the cost of 1,000 chatbot replies, with what differs. Price only, not quality.
Cheaper
- GPT-5.4 $9.750.93x the cost of a chatbot reply, OpenAI, 1.05M context vs 200K.
- GPT-5.2 $8.220.78x the cost of a chatbot reply, OpenAI, 400K context vs 200K.
- GPT-5.6 Terra $7.800.74x the cost of a chatbot reply, OpenAI, 1.05M context vs 200K.
Pricier
- Claude Opus 5.5 $14.001.33x the cost of a chatbot reply, same provider, 1M context vs 200K.
- GPT-5.6 Sol $14.001.33x the cost of a chatbot reply, OpenAI, 1.05M context vs 200K.
- GPT-5.5 $19.501.86x the cost of a chatbot reply, OpenAI, 1.05M context vs 200K.
Every price tier
| Input | $3 per 1M tokens |
| Output | $15 per 1M tokens |
| Cache write | $3.75 (5m), $6 (1h) |
| Cache read (hit) | $0.3 (10% of the input price) |
| Batch API | $1.5 input / $7.5 output |
| API model id | claude-sonnet-4-5-20250929 |
| Status on the pricing page | listed |
Provider notes: US-only inference (inference_geo "us") is 1.1x on Claude 4.6 and later
Model facts from Anthropic
| Context window | 200,000 tokens |
| Max output | 64,000 tokens |
| Input types | text, image |
| Lifecycle | deprecated |
| Provider note | Deprecated September 30, 2026; retires November 30, 2026. |
Source: https://platform.claude.com/docs/en/models/sonnet-4-5/overview, checked Oct 24, 2026.
The 6 classic workloads
Per 1,000 requests at the standard price. "With caching" bills the repeated part of the prompt at the cache-read price (cache writes not counted); "via batch" uses the batch API price. Run your own token counts in the LLM API cost calculator.
| Workload | Claude Sonnet 4.5per 1,000 requests |
|---|---|
| Chatbot replya 1,500-token prompt (1,000 of it a fixed system prompt) and a 400-token answer | $10.50$7.80 with caching |
| Answer from your docs (RAG)6,000 tokens of retrieved context plus the question, a 500-token answer | $25.50$22.80 with caching |
| Summarize a long documenta 20,000-token document in, an 800-token summary out | $72.00$69.30 with caching |
| Coding agent step40,000 tokens of repo context and history (30,000 of it repeated from the last step), 2,000 out | $150$69.00 with caching |
| Batch extraction2,000 tokens per record in, 300 tokens of JSON out, sent through the batch API where there is one | $10.50$5.25 via batch |
| Long-document Q&Aa 150,000-token contract or codebase in one prompt, a 1,000-token answer | $465 |
What the numbers say
- Output costs 5x input on Claude Sonnet 4.5, so for answer-heavy jobs the output price drives the bill; for document-heavy jobs (RAG, summaries, agents) input does.
- Caching matters: a coding-agent step that rereads 30,000 cached tokens costs 54% less than the same step uncached ($69.00 vs $150 per 1,000 steps, cache writes not counted). How to stop paying twice for repeated prompts: LLM semantic cache.
- Among 14 listed Anthropic models it is the #6 cheapest for a chat reply.
- Same standard input/output price as Claude Sonnet 4.6, Claude Sonnet 4; the differences are in caching, batch and long-prompt tiers.
Every listed Anthropic model, cheapest first
Same chatbot workload, 1,000 replies.
| Model | Input / 1M | Output / 1M | 1,000 chat replies |
|---|---|---|---|
| Claude Haiku 5.5 | $0.1 | $0.5 | $0.35 |
| Claude Haiku 4.5legacy | $1 | $5 | $3.50 |
| Claude Sonnet 5.5 | $2 | $10 | $7.00 |
| Claude Sonnet 5legacy | $2 | $10 | $7.00 |
| Claude Sonnet 4.6legacy | $3 | $15 | $10.50 |
| Claude Sonnet 4.5deprecated | $3 | $15 | $10.50 |
| Claude Opus 5.5 | $4 | $20 | $14.00 |
| Claude Opus 5legacy | $5 | $25 | $17.50 |
| Claude Opus 4.8legacy | $5 | $25 | $17.50 |
| Claude Opus 4.7legacy | $5 | $25 | $17.50 |
| Claude Opus 4.6legacy | $5 | $25 | $17.50 |
| Claude Opus 4.5legacy | $5 | $25 | $17.50 |
| Claude Fable 5.1 | $10 | $50 | $35.00 |
| Claude Fable 5legacy | $10 | $50 | $35.00 |
Closest price from other providers
The current model from each other provider whose chatbot-reply cost is nearest. Price only: we do not rank quality here.
| Model | Input / 1M | Output / 1M | 1,000 chat replies | vs Claude Sonnet 4.5 |
|---|---|---|---|---|
| GPT-5.4OpenAI | $2.5 | $15 | $9.75 | 0.93x |
| Gemini 3.1 Pro PreviewGoogle | $2 | $12 | $7.80 | 0.74x |
| DeepSeek V4 ProDeepSeek | $1.32 | $3.96 | $3.56 | 0.34x |
Price history
- Oct 23, 2026: Claude Sonnet 4.5 added to the table: $3 input / $15 output per 1M tokens.
- Checked against the provider page on 1 date: Oct 23, 2026.
Every change we record is on the LLM price changelog.
Sources
- Anthropic API pricing: https://platform.claude.com/docs/en/about-claude/pricing, checked Oct 23, 2026.
- Context, inputs and lifecycle: https://platform.claude.com/docs/en/models/sonnet-4-5/overview, checked Oct 24, 2026.
- Dataset: llm-prices (every row names its page and check date) and /llm/prices.csv.
Prices change often. If one is out of date, email matt@tensorust.com and we will fix it.