Model Comparison

Claude Opus 4.6 vs GPT-5.3 Codex

GPT-5.3 Codex significantly outperforms across most benchmarks. GPT-5.3 Codex is 2.1x cheaper per token.

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Performance Benchmarks

Comparative analysis across standard metrics

1 benchmarks

Claude Opus 4.6 outperforms in 0 benchmarks, while GPT-5.3 Codex is better at 1 benchmark (Terminal-Bench 2.0).

GPT-5.3 Codex significantly outperforms across most benchmarks.

Tue Apr 07 2026 • llm-stats.com

Arena Performance

Human preference votes

Pricing Analysis

Price comparison per million tokens

GPT-5.3 Codex costs less

For input processing, Claude Opus 4.6 ($5.00/1M tokens) is 2.9x more expensive than GPT-5.3 Codex ($1.75/1M tokens).

For output processing, Claude Opus 4.6 ($25.00/1M tokens) is 1.8x more expensive than GPT-5.3 Codex ($14.00/1M tokens).

In conclusion, Claude Opus 4.6 is more expensive than GPT-5.3 Codex.*

* Using a 3:1 ratio of input to output tokens

Lowest available price from all providers
Tue Apr 07 2026 • llm-stats.com
Anthropic
Claude Opus 4.6
Input tokens$5.00
Output tokens$25.00
Best providerAnthropic
OpenAI
GPT-5.3 Codex
Input tokens$1.75
Output tokens$14.00
Best providerOpenAI
Notice missing or incorrect data?Start an Issue→

Context Window

Maximum input and output token capacity

Claude Opus 4.6 accepts 1,000,000 input tokens compared to GPT-5.3 Codex's 400,000 tokens. Both models can generate responses up to 128,000 tokens.

Anthropic
Claude Opus 4.6
Input1,000,000 tokens
Output128,000 tokens
OpenAI
GPT-5.3 Codex
Input400,000 tokens
Output128,000 tokens
Tue Apr 07 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

Both Claude Opus 4.6 and GPT-5.3 Codex support multimodal inputs.

They are both capable of processing various types of data, offering versatility in application.

Claude Opus 4.6

Text
Images
Audio
Video

GPT-5.3 Codex

Text
Images
Audio
Video

License

Usage and distribution terms

Both models are licensed under proprietary licenses.

Both models have usage restrictions defined by their respective organizations.

Claude Opus 4.6

Proprietary

Closed source

GPT-5.3 Codex

Proprietary

Closed source

Release Timeline

When each model was launched

Both models were released on 2026-02-05.

They likely represent similar generations of model development.

Claude Opus 4.6

Feb 5, 2026

2 months ago

GPT-5.3 Codex

Feb 5, 2026

2 months ago

Knowledge Cutoff

When training data ends

Neither model specifies a knowledge cutoff date.

Unable to compare the recency of their training data.

No cutoff dates available

Provider Availability

Claude Opus 4.6 is available from Anthropic. GPT-5.3 Codex is available from OpenAI.

Claude Opus 4.6

anthropic logo
Anthropic
Input Price:Input: $5.00/1MOutput Price:Output: $25.00/1M

GPT-5.3 Codex

openai logo
OpenAI
Input Price:Input: $1.75/1MOutput Price:Output: $14.00/1M
* Prices shown are per million tokens

Outputs Comparison

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Key Takeaways

Anthropic
Larger context window (1,000,000 tokens)
OpenAI
Less expensive input tokens
Less expensive output tokens
Higher Terminal-Bench 2.0 score (77.3% vs 65.4%)

Detailed Comparison

AI Model Comparison Table
Feature
Anthropic
Claude Opus 4.6
OpenAI
GPT-5.3 Codex

FAQ

Common questions about Claude Opus 4.6 vs GPT-5.3 Codex

GPT-5.3 Codex significantly outperforms across most benchmarks. Claude Opus 4.6 is made by Anthropic and GPT-5.3 Codex is made by OpenAI. The best choice depends on your use case — compare their benchmark scores, pricing, and capabilities above.
Claude Opus 4.6 scores Vending-Bench 2: 100.0%, AIME 2025: 99.8%, Tau2 Telecom: 99.3%, Graphwalks parents >128k: 95.4%, MRCR v2 (8-needle): 93.0%. GPT-5.3 Codex scores SWE-Lancer (IC-Diamond subset): 81.4%, Cybersecurity CTFs: 77.6%, Terminal-Bench 2.0: 77.3%, OSWorld-Verified: 64.7%, SWE-Bench Pro: 56.8%.
GPT-5.3 Codex is 2.9x cheaper for input tokens. Claude Opus 4.6 costs $5.00/M input and $25.00/M output via anthropic. GPT-5.3 Codex costs $1.75/M input and $14.00/M output via openai.
Claude Opus 4.6 supports 1.0M tokens and GPT-5.3 Codex supports 400K tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.
Key differences include context window (1.0M vs 400K), input pricing ($5.00 vs $1.75/M). See the full comparison above for benchmark-by-benchmark results.
Claude Opus 4.6 is developed by Anthropic and GPT-5.3 Codex is developed by OpenAI.