Claude’s API pricing is token-based: you pay for the tokens you send (input) and the tokens Claude generates (output). Rate limits, service tiers, prompt caching, batch processing, and feature-specific charges all affect your actual bill. Last refreshed: October 5, 2026 (Pacific) against platform.claude.com pricing, Sonnet 5.5, and Opus 5.5. Claude list rates below did not move versus September 29.
Direct Answer (October 1, 2026): Official first-party list: Haiku 4.5 $1 / $5 per MTok; Sonnet 5.5 $2 / $10 (same unit price as Sonnet 5; Anthropic says fewer tokens per task); Sonnet 5 $2 / $10; Sonnet 4.6 and Sonnet 4.5 $3 / $15; Opus 5.5 $4 / $20 with cache reads at $0.20; Opus 5 / Opus 4.8 $5 / $25; Fable 5 and Mythos 5 $10 / $50 with cache reads at $1; Fable 5.1 and Mythos 5.1 $10 / $50 with cache reads at $0.25. Retired Opus 4 / 4.1 remain $15 / $75 where still hosted. Batch API is 50% off. Do not average Sonnet 5.5 with Sonnet 4.6.
Per-Token Pricing by Model
All prices are per million tokens (MTok), verified October 1, 2026. Claude Sonnet 5.5 remains $2 input / $10 output — the same list as Sonnet 5. Cache reads on Sonnet 5.5 are $0.20. Claude Opus 5.5 remains $4 / $20 with cache reads at $0.20. Fast mode for Opus 5.5 is $8 / $40. Sonnet 4.6 remains $3 / $15. Fable 5.1 keeps $10 / $50 with cache reads at $0.25.
Prompt Caching Pricing
5-minute cache write is 1.25x input. 1-hour cache write is 2x input. Cache read is 0.1x input on Sonnet 5.5 and Haiku 4.5, 0.05x on Opus 5.5. Fable 5.1 and Mythos 5.1 use 0.025x ($0.25/MTok). Opus 5.5 cache writes $5 / 1-hour $8 / reads $0.20. Opus 5 cache writes $6.25 / reads $0.50. Sonnet 5.5 and Sonnet 5 cache writes $2.50 / reads $0.20. Sonnet 4.6 cache writes $3.75 / reads $0.30. Haiku 4.5 cache writes $1.25 / reads $0.10.
Batch Processing: 50% Off
The Batch API processes requests asynchronously at half the standard rate. Sonnet 5.5 and Sonnet 5 batch list is $1 / $5. Sonnet 4.6 batch list is $1.50 / $7.50. Opus 5.5 batch is $2 / $10. Opus 5 batch is $2.50 / $12.50. Fable 5.1 batch is $5 / $25.
How to Calculate Your Monthly Bill
Example at Sonnet 5.5 / Sonnet 5 list ($2 / $10): 2,000 input tokens and 500 output tokens × 10,000 requests/day = 20 MTok input ($40) + 5 MTok output ($50) = $90/day, about $2,700/month before cache or batch. Same volume on Opus 5.5 at $4 / $20 is $180/day before cache. Same volume on Opus 5 at $5 / $25 is $225/day.
Same volume with caching: at a 90% cache-hit rate, 18 of those 20 MTok re-read from cache at $0.20/MTok ($3.60) instead of $2/MTok ($36) — input drops from $40 to $7.60/day, total roughly $57/day or ~$1,700/month. The cache line, not the input line, is usually what separates the sticker price from the real bill.
Service Tiers and Rate Limits
Priority, Standard, and Batch tiers still apply. US-only inference (inference_geo: "us") on Claude 4.6 and later is 1.1x. Fast mode on Opus 5.5 is $8 / $40. Fast mode on Opus 5 / Opus 4.8 is $10 / $50. Check live limits in the Claude Console; published RPM/ITPM figures move by spend tier. Confirm five-hour windows in Settings > Usage, not from a screenshot.
Frequently Asked Questions
How much does Claude API cost for a small project?
A small project making 100–500 API calls per day with Haiku 4.5 might cost $5–30/month. Sonnet 5.5 at the same volume is cheaper than Sonnet 4.6 because the list is $2 / $10, not $3 / $15.
Is there a free tier for the Claude API?
Anthropic does not offer a permanent free API tier. You need to add a payment method and load credits.
What’s the cheapest way to use the Claude API?
Use Haiku 4.5 ($1/MTok input), enable prompt caching, and batch non-real-time work (50% off). For mid-tier quality, prefer Sonnet 5.5 at $2 / $10 over Sonnet 4.6 at $3 / $15 unless you need the 4.6 SKU specifically. For Opus-class work, prefer Opus 5.5 at $4 / $20 over Opus 5 at $5 / $25 unless you are pinned to the older SKU.
How do Claude API costs compare to OpenAI?
OpenAI’s pricing docs list gpt-6.1-sol at $2 / $10 short-context standard (long-context $4 / $15) and GPT-5 at $1.25 / $10. The previous name on this page was GPT-6 Sol; the short-context pair did not move. Sonnet 5.5 at $2 / $10 sits level with gpt-6.1-sol short-context. Opus 5.5 at $4 / $20 costs twice that short-context pair. Fable 5.1 at $10 / $50 matches gpt-6-astra short-context on that page. Compare the exact SKU pair, not the family name.
What happens when I hit a Claude API rate limit?
The API returns HTTP 429. Back off and retry with exponential backoff; if you hit limits regularly, request a higher spend tier in the Claude Console. Our Claude rate limits guide covers the RPM/TPM tiers and the full 429 playbook.
Do cached tokens cost the same as fresh input?
No. Cache reads run 0.025×–0.10× the input price depending on model — $0.20/MTok on Sonnet 5.5, Sonnet 5, and Opus 5.5, $0.25 on Fable 5.1, $0.10 on Haiku 4.5. On cache-heavy workloads the read line sets your bill, not the input line.
Related: Claude AI pricing guide · Fable 5 pricing, cache rates & plan access · Claude rate limits & tiers · How to get an Anthropic API key · How much does Claude AI cost
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