Back to Audit
OPTERA LABS

Claude Opus 5 VS Gemini 3.1 Pro

2026 Cost & Performance Comparison
Model A · Anthropic

Claude Opus 5

claude-opus-5

Intelligence Score98%
Cost / 1M Tokens$11.00

70% in · 30% out mix

Value Index(score÷cost)
8.9

Higher = better value

Speed

63/100

Context

1.0M

Tier

power

Model B · Google

Gemini 3.1 Pro

gemini-3-1-pro

Intelligence Score89%
Cost / 1M Tokens$5.00

70% in · 30% out mix

Value Index(score÷cost)
17.8

Higher = better value

Speed

82/100

Context

2.0M

Tier

smart

IN-DEPTH ANALYSIS

Claude Opus 5 vs Gemini 3.1 Pro: Detailed Comparison

Claude Opus 5 is Anthropic's flagship-tier language model with a 1.0M-token context window, excelling at coding. Gemini 3.1 Pro from Google is a mid-range-tier model supporting 2.0M tokens in context, with standout performance in vision/multimodal.

Claude Opus 5 costs 2.2x what Gemini 3.1 Pro does per blended million tokens. That is a steep premium, and it buys a 20-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 is priced at $5.00/M input tokens and $25.00/M output tokens. Gemini 3.1 Pro costs $2.00/M input and $12.00/M output.

In independent benchmark evaluations, Claude Opus 5 leads with coding scores of 99/100 and reasoning scores of 98/100, compared to Gemini 3.1 Pro's 88/100 in coding and 89/100 in reasoning.

Capability breakdown

Across the five core benchmark categories, here is how Claude Opus 5 and Gemini 3.1 Pro stack up head to head:

coding
99
88
reasoning
98
89
data extraction
96
90
creative tasks
96
88
vision/multimodal
95
95

Best model by task

  • coding: Claude Opus 5 wins with 99/100
  • reasoning: Claude Opus 5 wins with 98/100
  • data extraction: Claude Opus 5 wins with 96/100
  • creative tasks: Claude Opus 5 wins with 96/100

Estimated monthly cost at scale

At 10M + 2M per month, Claude Opus 5 runs about $100.00 while Gemini 3.1 Pro runs about $44.00 — Gemini 3.1 Pro saves roughly $56.00 (56%) every month.

What actually decides it

Claude Opus 5 and Gemini 3.1 Pro come from different labs, which means different tokenizers, different API shapes, and a second vendor relationship. The same English text does not produce the same token count on both, so a price-per-million comparison understates the difference — measure your own prompts on each before treating the headline rates as the full story.

Claude Opus 5 and Gemini 3.1 Pro 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.

Gemini 3.1 Pro carries the larger context window at 2.0M tokens versus 1.0M for Claude Opus 5. The gap is real but not decisive — it matters if your prompts routinely run long, and is irrelevant if they sit where most production prompts sit, well under 100K. Bear in mind that filling a large window is also what makes a request expensive.

Latency separates them: Gemini 3.1 Pro scores 82/100 against 63/100 for Claude Opus 5, a 19-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 Opus 5 offers a batch API at 50% off standard rates, and Gemini 3.1 Pro 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 Opus 5 is 2.2x the price of Gemini 3.1 Pro. Reserve it for the requests that actually need it and route the rest to Gemini 3.1 Pro — that hybrid beats either model used alone on cost per useful answer.

Benchmark Comparison

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

CategoryClaude OpusGemini 3.1Winner

Coding

99
88
A

Reasoning

98
89
A

Extraction

96
90
A

Creative

96
88
A

Vision

95
95
Tied
Claude Opus 5: 4 wins
Gemini 3.1 Pro: 0 wins
Claude Opus 5 leads overall

Speed Score

63/100vs82/100
ClaudeGemini

Context Window

1000Kvs2000K
ClaudeGemini

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 Opus 5
$2.20
Gemini 3.1 Pro
$0.78

Business email

One typical email (~200 words)

~270 tokens
Claude Opus 5
$148.50
Gemini 3.1 Pro
$52.38

Code file

50-line Python script

~400 tokens
Claude Opus 5
$220.00
Gemini 3.1 Pro
$77.60

Prices shown are for 100,000 runs of each workload — one run costs a fraction of a cent on both Claude Opus 5 and Gemini 3.1 Pro, 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 Opus 5

$330.00/mo

$3,960.00/yr

$5/M in$25/M out
CHEAPER

Gemini 3.1 Pro

$150.00/mo

$1,800.00/yr

$2/M in$12/M out

Annual Savings

$2,160.00 saved per year

Gemini 3.1 Pro cheaper · $180.00/mo

Deep-Dive Audit — Claude Opus 5 & Gemini 3.1 Pro

SURGICAL AUDIT LABA7F6B2CC

Surgically Auditing: Deep Logic

Leakage Detected

3-YEAR STRATEGIC LOSS PROJECTION

$991.404

Without optimization protocols, current model choices will result in $330.468 capital loss per year.

EFFICIENCY SCORE

98%

Deep Logic

This model achieves a 98 benchmark score in this category.

CATEGORY GAP

2 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

%92

Operational Prescription

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

COST AUDIT PROTOCOL

Overkill Detected

"Claude Opus 5 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 $27.54/month."

3-Tier Intelligent Routing Architecture

92% 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 $3,965.616/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 5SELECTED
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 Opus
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

Related Comparisons

Explore similar model pairs to find your best fit

Claude OpusvsClaude Fable

$5 · $10/M in

Claude OpusvsGPT-5.6 Sol

$5 · $5/M in

Claude OpusvsClaude Opus

$5 · $5/M in

Claude OpusvsClaude Opus

$5 · $5/M in

Claude OpusvsClaude 3

$5 · $15/M in

Claude OpusvsGPT-5.6 Terra

$5 · $2/M in

Gemini 3.1vsGPT-5.6 Sol

$2 · $5/M in

Gemini 3.1vsGPT-5.6 Terra

$2 · $2/M in