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OPTERA LABS

GPT-5.2 Chat VS Claude 3.5 Sonnet

2026 Cost & Performance Comparison
Model A · OpenAI

GPT-5.2 Chat

gpt-5-2

Intelligence Score96%
Cost / 1M Tokens$5.43

70% in · 30% out mix

Value Index(score÷cost)
17.7

Higher = better value

Speed

85/100

Context

256K

Tier

smart

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

GPT-5.2 Chat vs Claude 3.5 Sonnet: Detailed Comparison

GPT-5.2 Chat is OpenAI's mid-range-tier language model with a 256K-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.

GPT-5.2 Chat is both the cheaper and the stronger model here — it costs 18% less than Claude 3.5 Sonnet on a typical prompt/completion mix and still leads on combined coding and reasoning by 1 points. There is no tradeoff to weigh on this pair: unless you need something specific from Claude 3.5 Sonnet, the cheaper model is simply the better one. GPT-5.2 Chat is priced at $1.75/M input tokens and $14.00/M output tokens. Claude 3.5 Sonnet costs $3.00/M input and $15.00/M output.

In independent benchmark evaluations, GPT-5.2 Chat leads with coding scores of 94/100 and reasoning scores of 96/100, compared to Claude 3.5 Sonnet's 96/100 in coding and 93/100 in reasoning.

Capability breakdown

Across the five core benchmark categories, here is how GPT-5.2 Chat and Claude 3.5 Sonnet stack up head to head:

coding
94
96
reasoning
96
93
data extraction
91
90
creative tasks
95
91
vision/multimodal
92
91

Best model by task

  • coding: Claude 3.5 Sonnet wins with 96/100
  • reasoning: GPT-5.2 Chat wins with 96/100
  • data extraction: GPT-5.2 Chat wins with 91/100
  • creative tasks: GPT-5.2 Chat wins with 95/100
  • vision/multimodal: GPT-5.2 Chat wins with 92/100

Estimated monthly cost at scale

At 10M + 2M per month, GPT-5.2 Chat runs about $45.50 while Claude 3.5 Sonnet runs about $60.00 — GPT-5.2 Chat saves roughly $14.50 (24%) every month.

What actually decides it

GPT-5.2 Chat and Claude 3.5 Sonnet 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.

GPT-5.2 Chat and Claude 3.5 Sonnet are 19 months apart, which is more than one generation in this market. Benchmark comparisons across that gap flatter the older model: it was measured against the evaluations that existed at the time. Treat Claude 3.5 Sonnet's scores as a floor for what it does well and be sceptical of a close-looking result.

Context is effectively a tie: 256K 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.

Throughput is close enough to ignore — 95/100 versus 85/100. Neither model will feel noticeably quicker in an interactive product, so latency is not a reason to choose between them.

GPT-5.2 Chat wins this comparison outright — cheaper and stronger. Choose Claude 3.5 Sonnet 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

CategoryGPT-5.2 ChatClaude 3.5Winner

Coding

94
96
B

Reasoning

96
93
A

Extraction

91
90
A

Creative

95
91
A

Vision

92
91
A
GPT-5.2 Chat: 4 wins
Claude 3.5 Sonnet: 1 wins
GPT-5.2 Chat leads overall

Speed Score

85/100vs95/100
GPT-5.2Claude

Context Window

256Kvs200K
GPT-5.2Claude

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
GPT-5.2 Chat
$0.70
Claude 3.5 Sonnet
$1.26

Business email

One typical email (~200 words)

~270 tokens
GPT-5.2 Chat
$47.25
Claude 3.5 Sonnet
$85.05

Code file

50-line Python script

~400 tokens
GPT-5.2 Chat
$70.00
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 GPT-5.2 Chat 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%
CHEAPER

GPT-5.2 Chat

$162.75/mo

$1,953.00/yr

$1.75/M in$14/M out

Claude 3.5 Sonnet

$198.00/mo

$2,376.00/yr

$3/M in$15/M out

Annual Savings

$423.00 saved per year

GPT-5.2 Chat cheaper · $35.25/mo

Deep-Dive AuditGPT-5.2 Chat & Claude 3.5 Sonnet

SURGICAL AUDIT LABD6E2BABB

Surgically Auditing: Deep Logic

Leakage Detected

3-YEAR STRATEGIC LOSS PROJECTION

$478.404

Without optimization protocols, current model choices will result in $159.468 capital loss per year.

EFFICIENCY SCORE

96%

Deep Logic

This model achieves a 96 benchmark score in this category.

CATEGORY GAP

4 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

%84

Operational Prescription

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

COST AUDIT PROTOCOL

Overkill Detected

"GPT-5.2 Chat 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 $13.29/month."

3-Tier Intelligent Routing Architecture

84% 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 $1,913.616/year in avoidable overhead.

Deep LogicModel Cost / Quality Matrix

Source: MMLU-Pro + GPQA Diamond (Apr 2026)
ModelBenchmarkInput (per M)Output (per M)Annual Cost*Value Index
o3-miniBEST VALUE
97/100
$1.10$4.40$66.00
100/100
GPT-5.2 ChatSELECTED
96/100
$1.75$14.00$189.00
35/100
Claude 3.7 Sonnet
95/100
$3.00$15.00$216.00
30/100
GPT-5.6 Terra
94/100
$2.00$12.00$168.00
38/100
Claude 3.5 Sonnet
93/100
$3.00$15.00$216.00
29/100
GPT-4.1
93/100
$2.00$8.00$120.00
53/100
Claude Sonnet 5
92/100
$3.00$15.00$216.00
29/100
Grok 4.5
90/100
$2.00$6.00$96.00
64/100
GPT-4o
90/100
$2.50$10.00$150.00
41/100
Gemini 3.1 Pro
89/100
$2.00$12.00$168.00
36/100
Gemini 2.0 Pro
88/100
$1.25$5.00$75.00
80/100
Gemini 1.5 Pro
87/100
$1.25$5.00$75.00
79/100
Mistral Large 2
86/100
$2.00$6.00$96.00
61/100

* 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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