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OPTERA LABS

Claude 3 Opus VS Claude 3.5 Sonnet

2026 Cost & Performance Comparison
Model A · Anthropic

Claude 3 Opus

claude-3-opus

Intelligence Score90%
Cost / 1M Tokens$33.00

70% in · 30% out mix

Value Index(score÷cost)
2.7

Higher = better value

Speed

50/100

Context

200K

Tier

power

Model B · Anthropic

Claude 3.5 Sonnet

claude-3-5-sonnet

Intelligence Score93%
Cost / 1M Tokens$6.60

70% in · 30% out mix

Value Index(score÷cost)
14.1

Higher = better value

Speed

95/100

Context

200K

Tier

smart

IN-DEPTH ANALYSIS

Claude 3 Opus vs Claude 3.5 Sonnet: Detailed Comparison

Claude 3 Opus is Anthropic's flagship-tier language model with a 200K-token context window, excelling at reasoning. Claude 3.5 Sonnet from Anthropic is a mid-range-tier model supporting 200K tokens in context, with standout performance in coding.

Claude 3.5 Sonnet is both the cheaper and the stronger model here — it costs 80% less than Claude 3 Opus on a typical prompt/completion mix and still leads on combined coding and reasoning by 19 points. There is no tradeoff to weigh on this pair: unless you need something specific from Claude 3 Opus, the cheaper model is simply the better one. Claude 3 Opus is priced at $15.00/M input tokens and $75.00/M output tokens. Claude 3.5 Sonnet costs $3.00/M input and $15.00/M output.

In independent benchmark evaluations, Claude 3.5 Sonnet leads with coding scores of 96/100 and reasoning scores of 93/100, compared to Claude 3 Opus's 80/100 in coding and 90/100 in reasoning.

Capability breakdown

Across the five core benchmark categories, here is how Claude 3 Opus and Claude 3.5 Sonnet stack up head to head:

coding
80
96
reasoning
90
93
data extraction
85
90
creative tasks
89
91
vision/multimodal
87
91

Best model by task

  • coding: Claude 3.5 Sonnet wins with 96/100
  • reasoning: Claude 3.5 Sonnet wins with 93/100
  • data extraction: Claude 3.5 Sonnet wins with 90/100
  • creative tasks: Claude 3.5 Sonnet wins with 91/100
  • vision/multimodal: Claude 3.5 Sonnet wins with 91/100

Estimated monthly cost at scale

At 10M + 2M per month, Claude 3 Opus runs about $300.00 while Claude 3.5 Sonnet runs about $60.00 — Claude 3.5 Sonnet saves roughly $240.00 (80%) 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 3.5 Sonnet and Claude 3 Opus were released within 3 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: 200K against 200K. 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 3.5 Sonnet scores 95/100 against 50/100 for Claude 3 Opus, a 45-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.

One practical asymmetry: Claude 3.5 Sonnet offers a batch API at 50% off standard rates, and Claude 3 Opus does not. For anything that does not need an answer immediately — nightly enrichment, backfills, evaluation runs — that discount can be worth more than the difference in list price, and it is easy to overlook when comparing headline rates.

Claude 3.5 Sonnet wins this comparison outright — cheaper and stronger. Choose Claude 3 Opus only if it has a specific capability you need; on price and benchmarks it is behind on both.

Benchmark Comparison

Head-to-head scores across 5 categories — sourced from official evals

CategoryClaude 3Claude 3.5Winner

Coding

80
96
B

Reasoning

90
93
B

Extraction

85
90
B

Creative

89
91
B

Vision

87
91
B
Claude 3 Opus: 0 wins
Claude 3.5 Sonnet: 5 wins
Claude 3.5 Sonnet leads overall

Speed Score

50/100vs95/100
ClaudeClaude

Context Window

200Kvs200K
ClaudeClaude

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!"

4 tokens
Claude 3 Opus
$6.48
Claude 3.5 Sonnet
$1.26

Business email

One typical email (~200 words)

~270 tokens
Claude 3 Opus
$437.40
Claude 3.5 Sonnet
$85.05

Code file

50-line Python script

~400 tokens
Claude 3 Opus
$648.00
Claude 3.5 Sonnet
$126.00

Prices shown are for 100,000 runs of each workload — one run costs a fraction of a cent on both Claude 3 Opus and Claude 3.5 Sonnet, 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_tokens

Every 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

30.0M TOKENS
Prompt 70%Completion 30%

Claude 3 Opus

$990.00/mo

$11,880.00/yr

$15/M in$75/M out
CHEAPER

Claude 3.5 Sonnet

$198.00/mo

$2,376.00/yr

$3/M in$15/M out

Annual Savings

$9,504.00 saved per year

Claude 3.5 Sonnet cheaper · $792.00/mo

Deep-Dive Audit — Claude 3 Opus & Claude 3.5 Sonnet

SURGICAL AUDIT LAB9DD06D17

Surgically Auditing: Deep Logic

Leakage Detected

3-YEAR STRATEGIC LOSS PROJECTION

$3,151.404

Without optimization protocols, current model choices will result in $1,050.468 capital loss per year.

EFFICIENCY SCORE

90%

Deep Logic

This model achieves a 90 benchmark score in this category.

CATEGORY GAP

10 pts

Distance from Leader

Competitive Landscape Analysis

Source: MMLU-Pro + GPQA Diamond (Apr 2026)

Category Champion: Claude Fable 5

According to MMLU-Pro + GPQA Diamond (Apr 2026) data, Claude Fable 5 provides the optimum balance for Deep Logic tasks.

Market Score

%100

Savings Rate

%97

Operational Prescription

  • Implement model cascading to optimize token spend.
  • Analyze complex_reasoning data to leverage local semantic caching.

COST AUDIT PROTOCOL

Overkill Detected

"Claude 3 Opus is overpriced for this task type. Claude Fable 5 scores 100 in this category at a fraction of the cost."

Categorical Alternative Opportunity

"Claude Fable 5 leads this category with 100 points according to MMLU-Pro + GPQA Diamond (Apr 2026) data."

Inertia Tax Detected

"85% of traffic can be routed to cheaper models. Fast tier (GPT-5 Nano) and Smart tier (o3-mini) can save $87.54/month."

3-Tier Intelligent Routing Architecture

97% SAVINGS VIA ROUTING
Fast Tier
50%

GPT-5 Nano

IQ Score: 72/100

$18.00/yr

Smart Tier
35%

o3-mini

IQ Score: 97/100

$277.20/yr

Power Tier
15%

DeepSeek R1

IQ Score: 97/100

$59.184/yr

Fast Tier 50%Smart Tier 35%Power Tier 15%

Without tiered routing, you pay the 'Inertia Tax' — routing all traffic to the most expensive model regardless of task complexity. Tiered cascade eliminates $12,605.616/year in avoidable overhead.

Deep Logic — Model Cost / Quality Matrix

Source: MMLU-Pro + GPQA Diamond (Apr 2026)
ModelBenchmarkInput (per M)Output (per M)Annual Cost*Value Index
Claude Fable 5LEADER
100/100
$10.00$50.00$720.00
5/100
GPT-5.6 Sol
99/100
$5.00$30.00$420.00
8/100
Claude Opus 5
98/100
$5.00$25.00$360.00
9/100
Claude Opus 4.6
98/100
$5.00$25.00$360.00
9/100
o3-mini
97/100
$1.10$4.40$66.00
50/100
DeepSeek R1BEST VALUE
97/100
$0.55$2.19$32.88
100/100
Claude Opus 4.8
96/100
$5.00$25.00$360.00
9/100
GPT-5.2 Chat
96/100
$1.75$14.00$189.00
17/100
Claude 3.7 Sonnet
95/100
$3.00$15.00$216.00
15/100
GPT-5.6 Terra
94/100
$2.00$12.00$168.00
19/100
Claude 3.5 Sonnet
93/100
$3.00$15.00$216.00
15/100
GPT-4.1
93/100
$2.00$8.00$120.00
26/100
Claude Sonnet 5
92/100
$3.00$15.00$216.00
14/100
Claude 3 OpusSELECTED
90/100
$15.00$75.00$1,080.00
3/100
Grok 4.5
90/100
$2.00$6.00$96.00
32/100
GPT-4o
90/100
$2.50$10.00$150.00
20/100
Gemini 3.1 Pro
89/100
$2.00$12.00$168.00
18/100
Gemini 2.0 Pro
88/100
$1.25$5.00$75.00
40/100
Llama 3.1 405B
88/100
$2.70$2.70$64.80
46/100
Gemini 1.5 Pro
87/100
$1.25$5.00$75.00
39/100
Mistral Large 2
86/100
$2.00$6.00$96.00
30/100

* Annual cost for given volumes. Value Index = Score / Cost (Higher = Best Value).

Tactical Code Gen
// iOPTERA Surgical Routing Wrapper
const auditModel = async (prompt: string) => {
  const complexity = measureComplexity(prompt);
  
  // Tactical Cascade Logic
  if (complexity < 0.45) {
    // Redirect simple tasks to efficient model
    return await llm.call("iOPTERA Optimization", prompt); 
  }
  
  // High-latency routing for complex reasoning
  return await llm.call("Claude Fable 5", prompt);
};
READY TO DEPLOY IN Vercel Edge OR AWS Lambda

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