What is GPT-5.3 best for?

GPT-5.3 excels at coding, analysis, math, general, writing. It is a frontier-tier model from OpenAI with reasoning capabilities and vision support.

How does GPT-5.3 compare to alternatives?

With a quality score of 70 and a speed of 80 tokens per second, GPT-5.3 sits in the frontier tier. Comparable models include Claude Opus 4.5 and Claude Sonnet 4.5. Use our benchmark dashboard or comparison pages to see detailed side-by-side differences.

What context window does GPT-5.3 support?

GPT-5.3 supports a context window of 400K tokens with a maximum output of 64K tokens. This is a large context model suitable for processing long documents.

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Models/GPT-5.3

GPT-5.3

by OpenAI · Released 2026-02

Frontier

Overview

GPT-5.3 is a frontier-class model representing the cutting edge of AI capability, developed by OpenAI. It achieves a quality score of 70 on the Artificial Analysis Intelligence Index, placing it among the top-performing models currently available.

This model is particularly strong at coding, analysis, math, general, writing. It supports chain-of-thought reasoning, which helps with complex multi-step problems. It also handles image inputs, making it suitable for visual understanding tasks.

At $2.00 per 1M input tokens and $10.00 per 1M output tokens, running 500 tasks per month (at ~45K tokens each) would cost approximately $117.00/month. Compare this with alternatives using our cost calculator to find the best fit for your budget.

Quality Score

Input Price

$2.00/1M

Output Price

$10.00/1M

Context Window

400K

Max Output

64K

Speed

80 tok/s

Reasoning