Model Comparison

Claude Haiku 4.5 vs GPT-5.3 Codex

GPT-5.3 Codex significantly outperforms across most benchmarks. Claude Haiku 4.5 is 2.4x cheaper per token.

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Performance Benchmarks

Comparative analysis across standard metrics

1 benchmarks

Claude Haiku 4.5 outperforms in 0 benchmarks, while GPT-5.3 Codex is better at 1 benchmark (Cybersecurity CTFs).

GPT-5.3 Codex significantly outperforms across most benchmarks.

Wed Apr 15 2026 • llm-stats.com

Arena Performance

Human preference votes

Pricing Analysis

Price comparison per million tokens

Claude Haiku 4.5 costs less

For input processing, Claude Haiku 4.5 ($1.00/1M tokens) is 1.8x cheaper than GPT-5.3 Codex ($1.75/1M tokens).

For output processing, Claude Haiku 4.5 ($5.00/1M tokens) is 2.8x cheaper than GPT-5.3 Codex ($14.00/1M tokens).

In conclusion, GPT-5.3 Codex is more expensive than Claude Haiku 4.5.*

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

Lowest available price from all providers
Wed Apr 15 2026 • llm-stats.com
Anthropic
Claude Haiku 4.5
Input tokens$1.00
Output tokens$5.00
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

GPT-5.3 Codex accepts 400,000 input tokens compared to Claude Haiku 4.5's 200,000 tokens. GPT-5.3 Codex can generate longer responses up to 128,000 tokens, while Claude Haiku 4.5 is limited to 64,000 tokens.

Anthropic
Claude Haiku 4.5
Input200,000 tokens
Output64,000 tokens
OpenAI
GPT-5.3 Codex
Input400,000 tokens
Output128,000 tokens
Wed Apr 15 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

Both Claude Haiku 4.5 and GPT-5.3 Codex support multimodal inputs.

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

Claude Haiku 4.5

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 Haiku 4.5

Proprietary

Closed source

GPT-5.3 Codex

Proprietary

Closed source

Release Timeline

When each model was launched

Claude Haiku 4.5 was released on 2025-10-15, while GPT-5.3 Codex was released on 2026-02-05.

GPT-5.3 Codex is 4 months newer than Claude Haiku 4.5.

Claude Haiku 4.5

Oct 15, 2025

6 months ago

GPT-5.3 Codex

Feb 5, 2026

2 months ago

3mo newer

Knowledge Cutoff

When training data ends

Claude Haiku 4.5 has a documented knowledge cutoff of 2025-02-01, while GPT-5.3 Codex's cutoff date is not specified.

We can confirm Claude Haiku 4.5's training data extends to 2025-02-01, but cannot make a direct comparison without GPT-5.3 Codex's cutoff date.

Claude Haiku 4.5

Feb 2025

GPT-5.3 Codex

—

Provider Availability

Claude Haiku 4.5 is available from Anthropic. GPT-5.3 Codex is available from OpenAI.

Claude Haiku 4.5

anthropic logo
Anthropic
Input Price:Input: $1.00/1MOutput Price:Output: $5.00/1M

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

Notice missing or incorrect data?Start an Issue discussion→

Key Takeaways

Anthropic
Less expensive input tokens
Less expensive output tokens
OpenAI
Larger context window (400,000 tokens)
Higher Cybersecurity CTFs score (77.6% vs 46.9%)

Detailed Comparison

AI Model Comparison Table
Feature
Anthropic
Claude Haiku 4.5
OpenAI
GPT-5.3 Codex

FAQ

Common questions about Claude Haiku 4.5 vs GPT-5.3 Codex

GPT-5.3 Codex significantly outperforms across most benchmarks. Claude Haiku 4.5 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 Haiku 4.5 scores Tau2 Retail: 83.2%, MMMLU: 83.0%, Tau2 Telecom: 83.0%, AIME 2025: 80.7%, SWE-Bench Verified: 73.3%. 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%.
Claude Haiku 4.5 is 1.8x cheaper for input tokens. Claude Haiku 4.5 costs $1.00/M input and $5.00/M output via anthropic. GPT-5.3 Codex costs $1.75/M input and $14.00/M output via openai.
Claude Haiku 4.5 supports 200K 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 (200K vs 400K), input pricing ($1.00 vs $1.75/M). See the full comparison above for benchmark-by-benchmark results.
Claude Haiku 4.5 is developed by Anthropic and GPT-5.3 Codex is developed by OpenAI.