Model Comparison
GPT-4o (ChatGPT)
vs. GPT-5.3 Codex (xhigh)
Comparing 2 AI models · 10 benchmarks · OpenAI
Recommended Pick
Op GPT-5.3 Codex (xhigh) 7 metric wins Strongest on: Throughput, Reasoning, Intelligence
Lowest Price
GPT-4o (ChatGPT)
$0.00/1M input price
Best Reasoning
GPT-5.3 Codex (xhigh)
61.7 reasoning score
Blends available reasoning benchmarks
Best for Coding
GPT-5.3 Codex (xhigh)
53.1 coding index
Composite Indices
Higher is better; speed and price are normalized
Standard Benchmarks
Only benchmarks with data are shown
Differences That Matter
Price gap
GPT-4o (ChatGPT) is ∞x cheaper on input tokens than GPT-5.3 Codex (xhigh).
Reasoning gap
GPT-5.3 Codex (xhigh) leads GPT-4o (ChatGPT) by 29.9 points on reasoning.
Top-pick rationale
GPT-5.3 Codex (xhigh) wins 7 measurable categories, including Throughput, Reasoning, Intelligence, GPQA.
Response Face-Off
Run one prompt through the selected models and compare response quality with live speed and cost context.
GPT-4o (ChatGPT)
OpenAI
TTFT
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Time
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tok/s
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Tokens
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Cost
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GPT-5.3 Codex (xhigh)
OpenAI
TTFT
—
Time
—
tok/s
—
Tokens
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Cost
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Which answer was more useful?
Full Comparison
| Metric | Op GPT-4o (ChatGPT) | Top Pick Op GPT-5.3 Codex (xhigh) |
|---|---|---|
| Pricing per 1M tokens | ||
| Input Cost | $0.00/1M | $1.75/1M |
| Output Cost | $0.00/1M | $14.00/1M |
| Blended (3:1) | — | $4.81/1M |
| Specifications | ||
| Organization | OpenAI | OpenAI |
| Release Date | Feb 15, 2025 | Feb 5, 2026 |
| Performance & Speed | ||
| Throughput | — | 90.1 tok/s |
| TTFT | — | 95129ms |
| Latency | — | 95129ms |
| Composite Indices | ||
| Value Score | — | 100.0 |
| Reasoning Score | 31.8 | 61.7 |
| Intelligence | 14.1 | 53.6 |
| Coding | — | 53.1 |
| Standard Benchmarks | ||
| GPQA | 51.1% | 91.5% |
| MMLU Pro | 77.3% | — |
| HLE | 3.7% | 39.9% |
| MATH 500 | 79.7% | — |
| AIME (Original) | 10.3% | — |
| SciCode | 33.4% | 53.2% |
| LCR | 53.0% | 74.0% |
| IFBench | — | 75.4% |
| TAU-bench v2 | — | 86.0% |
| TerminalBench Hard | — | 53.0% |
Key Takeaways
GPT-4o (ChatGPT) offers the best value at $0.00/1M, making it ideal for high-volume applications and cost-conscious projects.
GPT-5.3 Codex (xhigh) has the strongest reasoning profile with a 61.7 reasoning score, combining the available reasoning-heavy benchmarks.
GPT-5.3 Codex (xhigh) reaches a 53.1 coding index, making it the top choice for software development and code generation tasks.
All models support context windows of ∞+ tokens, suitable for processing lengthy documents and maintaining extended conversations.
When to Choose Each Model
GPT-4o (ChatGPT)
- Cost-sensitive applications
- High-volume processing
GPT-5.3 Codex (xhigh)
- Complex reasoning tasks
- Research & analysis
- Code generation
- Software development
