OpenAI: GPT-5.3-Codex

Public pricingIntelligence 83/100Large memoryVisionDeep thinkingTool use

OpenAI: GPT-5.3-Codex is a multimodal model for coding, software engineering, and agent workflows. It combines multimodal input handling and strong coding performance with a 400K tokens context window and a balanced-cost profile. Use it for coding, software engineering, and agent workflows when accuracy, context, and control matters.

Input

$1.75/1M

Output

$14.00/1M

Cached

$0.17/1M

Batch

$0.88/1M

Calculate your GPT-5.3-Codex bill.

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What would GPT-5.3-Codex cost you?

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Technical specifications

GPT-5.3-Codex at a glance.

Memory

400,000

tokens

Max reply

128,000

tokens

Memory tier

Large

an entire book or large codebase

Tokenizer

tiktoken-o200k

Released

Feb 2026

Training cutoff

Jul 2025

Availability

Public pricing

Status

active

Benchmarks

Quality benchmarks

Independent evaluations from public leaderboards. Higher is better.

  • gpqa_diamond

    91.5

  • aa_intelligence_index

    54

  • swe_bench_verified

    74.79

What it can do

Capabilities & limits.

  • Understands images
  • Deep step-by-step thinking
  • Uses tools / calls functions
  • Strict JSON output
  • Streams replies
  • Fine-tunable on your data

When to pick GPT-5.3-Codex

  • Multi-step reasoning, research agents, or hard math.
  • Screenshot analysis, image understanding, or document OCR.
  • Agentic workflows that call tools or APIs.
  • Long documents, full codebases, or extensive chat histories.

When to look elsewhere

  • Very latency-sensitive, real-time apps where every millisecond counts.

Alternatives

Similar models to compare.

FAQ

GPT-5.3-Codex — the questions we see most.

Pricing, capabilities, alternatives — generated from the same data that powers the calculator above.

Get instant answers from our AI agent

At a typical workload of 50,000 conversations a month with 1,500-token prompts and 800-token replies, GPT-5.3-Codex costs roughly $691 per month. Input is $1.75 /1M tokens and output is $14.00 /1M tokens.
GPT-5.3-Codex has a 400,000-token context window (large memory — an entire book or large codebase). That means you can fit about 75,000 words of input and history in a single call.
Beyond text generation, GPT-5.3-Codex supports understanding images, deep step-by-step reasoning, calling functions / tools, strict JSON output, fine-tuning on your own data. It streams replies by default.
GPT-5.3-Codex was released in February 2026, with training data cut off around July 2025.
Models in a similar class include GPT-5.2, GPT-5.2-Codex, o3. The "Similar models" section below this FAQ links into each.

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