Cost and performance comparison
Claude Opus 5.5 vs Claude Sonnet 5.5
Model AAnthropic
Claude Opus 5.5
- Cost / 1M Tokens
- $8.80
- 70% in · 30% out mix
- ≈ $12.58 for the same text, tokenizer included
- Value Index (score÷cost)
- 7.9
- Higher = better value
- Speed
- 66/100
- Context
- 1.0M
- Tier
- Power Tier
List price from the Anthropic pricing page, verified October 12, 2026.
Its tokenizer produces about 43% more tokens than OpenAI's for the same text, so the real cost runs higher than the list price suggests. This is an estimate: the tokenizer has not been measured yet.
Check the sourceModel BAnthropic
Claude Sonnet 5.5
- Cost / 1M Tokens
- $4.40
- 70% in · 30% out mix
- ≈ $6.29 for the same text, tokenizer included
- Value Index (score÷cost)
- 14.9
- Higher = better value
- Speed
- 91/100
- Context
- 1.0M
- Tier
- Smart Tier
List price from the Anthropic pricing page, verified October 12, 2026.
Its tokenizer produces about 43% more tokens than OpenAI's for the same text, so the real cost runs higher than the list price suggests. This is an estimate: the tokenizer has not been measured yet.
Check the sourceIn-depth analysis
Claude Opus 5.5 vs Claude Sonnet 5.5: Detailed Comparison
Claude Opus 5.5 is Anthropic's flagship-tier language model with a 1.0M-token context window, excelling at coding. Claude Sonnet 5.5 from Anthropic is a mid-range-tier model supporting 1.0M tokens in context, with standout performance in coding.
Claude Opus 5.5 costs 2.0x what Claude Sonnet 5.5 does for the same text. That is a steep premium, and it buys a 7-point lead on combined coding and reasoning. Whether that trade is worth it depends entirely on how much of your traffic actually needs the harder model — for most workloads the honest answer is a small fraction of it, which is an argument for routing rather than for picking one. Claude Opus 5.5 is priced at $4.00/M input tokens and $20.00/M output tokens. Claude Sonnet 5.5 costs $2.00/M input and $10.00/M output.
On iOPTERA's editorial scores, Claude Opus 5.5 leads with 99/100 for coding and 99/100 for reasoning, against Claude Sonnet 5.5's 97/100 and 94/100.
Capability breakdown
Across the five core benchmark categories, here is how Claude Opus 5.5 and Claude Sonnet 5.5 stack up head to head:
Best model by task
- coding: Claude Opus 5.5 wins with 99/100
- reasoning: Claude Opus 5.5 wins with 99/100
- data extraction: Claude Opus 5.5 wins with 97/100
- creative tasks: Claude Opus 5.5 wins with 97/100
- vision/multimodal: Claude Opus 5.5 wins with 96/100
Estimated monthly cost at scale
For 10M + 2M tokens of text a month (counted the way OpenAI's tokenizer counts), Claude Opus 5.5 runs about $114.40 while Claude Sonnet 5.5 runs about $57.20 — Claude Sonnet 5.5 saves roughly $57.20 (50%) every month.
What actually decides it
Both models come from Anthropic, so they share a tokenizer, an API surface, and a billing account. Switching between them is a model-string change and nothing else — no new SDK, no re-tokenizing your prompts to re-estimate cost, no second vendor to onboard. That makes routing between them far cheaper to implement than a cross-vendor split.
Claude Opus 5.5 and Claude Sonnet 5.5 were released within 0 months of each other, so they are competing on the same evaluations under roughly the same conditions. That makes a direct benchmark comparison meaningful here in a way it usually is not — neither model has the advantage of being measured on a newer, easier set of tests.
Context is effectively a tie: 1.0M against 1.0M. Neither model unlocks a document size the other cannot handle, so this axis should not enter the decision. If you were hoping context would break the tie for you, it will not.
Latency separates them: Claude Sonnet 5.5 scores 91/100 against 66/100 for Claude Opus 5.5, a 25-point gap. That matters for anything a person waits on — chat, autocomplete, interactive tools. For batch and background work it does not, and trading latency for capability there is usually the right call.
Claude Opus 5.5 is 2.0x the price of Claude Sonnet 5.5. Reserve it for the requests that actually need it and route the rest to Claude Sonnet 5.5 — that hybrid beats either model used alone on cost per useful answer.
What you actually pay
The list price is only the start. Prompt caching, batch processing and long prompts change the bill, and each provider sets them differently. Prices per 1M tokens.
| Pricing term | Claude Opus 5.5 | Claude Sonnet 5.5 |
|---|---|---|
| List price (input / output) | $4.00 / $20.00 | $2.00 / $10.00 |
| Cached input | $0.205% of the input price | $0.105% of the input price |
| Batch API | 50% off input and output | 50% off input and output |
| Long prompts | No surcharge across the 1M window | No surcharge across the 1M window |
| Input with 80% cache hits | $0.96 | $0.48 |
With 80% of input served from the cache, Claude Sonnet 5.5 costs 50% less than Claude Opus 5.5 for the same input text, counting each model's tokenizer.The tokenizer factor for Claude Opus 5.5, Claude Sonnet 5.5 is our estimate until it is measured.
The last row assumes 80% of input tokens are read from the cache, as in a chat app that re-sends a long system prompt or RAG over the same documents. Cache-write and storage charges are not included.
Claude also bills cache writes: 1.25× the input price for a 5-minute cache, 2× for one hour.
Checked on October 8, 2026 against the pricing pages of Anthropic.
Capability scores
iOPTERA editorial scores across 5 categories — informed by public benchmarks, not measured by us
Coding
Reasoning
Extraction
Creative
Vision
Speed Score
Context Window
What Is a Token?
Models don't read words — they process tokens.
A token is roughly 4 characters of English text (~¾ of a word). Your API bill is priced per million tokens — understanding this directly reduces your costs.
Short phrase
"Hello, world!"
- Claude Opus 5.5
- $2.29
- Claude Sonnet 5.5
- $1.14
Business email
One typical email (~200 words)
- Claude Opus 5.5
- $154.44
- Claude Sonnet 5.5
- $77.22
Code file
50-line Python script
- Claude Opus 5.5
- $228.80
- Claude Sonnet 5.5
- $114.40
Prices shown are for 100,000 runs of each workload — one run costs a fraction of a cent on both Claude Opus 5.5 and Claude Sonnet 5.5, so the number only becomes meaningful at production volume. Input tokens only; add your output volume in the calculator below.
How to check your token usage
response.usage.total_tokensEvery API response includes a usage object. Sum total_tokens across all calls to get your monthly figure, then use the calculator below.
Your Cost Calculator
Enter your actual monthly token usage to see real savings
Quick Presets
Claude Opus 5.5
$377.52/mo
$4,530.24/yr
Claude Sonnet 5.5
$188.76/mo
$2,265.12/yr
Annual Savings
$2,265.12 saved per year
Claude Sonnet 5.5 cheaper · $188.76/mo
Related Comparisons
Explore similar model pairs to find your best fit
Claude OpusvsClaude Opus
$4.00 · $5.00/M input
Claude OpusvsClaude Fable
$4.00 · $10.00/M input
Claude OpusvsGPT-6 Astra
$4.00 · $10.00/M input
Claude OpusvsClaude 3
$4.00 · $15.00/M input
Claude SonnetvsClaude Sonnet
$2.00 · $2.00/M input
Claude SonnetvsGemini 3.1
$2.00 · $2.00/M input
Claude SonnetvsGPT-6.1 Sol
$2.00 · $2.00/M input
Claude SonnetvsGrok 4.7
$2.00 · $2.00/M input