GPT-5.3 Codex vs Claude Opus 4.8 — Coding AI Pricing 2026

GPT-5.3 Codex is 65% cheaper on input and 44% cheaper on output than Claude Opus 4.8 — purpose-built for coding at a lower price.

Pricing data verified: Jun 10, 2026

Cheapest Input
GPT-5.3 Codex
$1.75 vs $5.00 per 1M tokens
Context Window
Claude Opus 4.8
1M vs 400K tokens (2.5x larger)
Best for Coding
GPT-5.3 Codex
65% cheaper input, 44% cheaper output

Coding AI Models Compared

Coding-focused and general-purpose models from major providers, ranked by input price.

Model Provider Tier Input (per 1M) Output (per 1M) Context
GPT-5 OpenAI Budget $2.50 $10.00 272K
GPT-5.3 Codex OpenAI Mid $1.75 $14.00 400K
Claude Sonnet 4.6 Anthropic Budget $3.00 $15.00 200K
Gemini 3.1 Pro Google Budget $3.50 $10.50 1M
Claude Opus 4.8 Anthropic Premium $5.00 $25.00 1M
Gemini 3.5 Flash Google Premium $12.00 $36.00 1M
GPT-5.5 OpenAI Premium $15.00 $60.00 512K
GPT-5.5 Pro OpenAI Premium $30.00 $180.00 1.05M

Calculate Your Exact Costs

Pick your models, enter your usage, see how much you'd save with GPT-5.3 Codex for coding tasks.

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Anthropic
Claude Opus 4.8
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Enter your usage above to see savings.

Which Should You Choose?

Code Generation

Writing new functions, classes, and modules from prompts. GPT-5.3 Codex is purpose-built for this and costs 65% less on input.

Pick GPT-5.3 Codex: At $1.75/$14 vs Opus 4.8's $5/$25, you save 65% on input and 44% on output. Codex is optimized for code generation tasks at a lower price point.

Code Review

Analyzing pull requests, finding bugs, and suggesting improvements. Both models handle this well, but cost scales with volume.

Pick GPT-5.3 Codex: At $1.75 input, reviewing 1,000 PRs/month with 4K input tokens each costs $7 vs $20 with Opus 4.8 — saving $13/month.

Refactoring

Rewriting and restructuring existing code. Requires understanding large code chunks but not necessarily the entire codebase.

Pick GPT-5.3 Codex: 400K context handles most refactoring tasks. At 65% lower input cost, you can refactor more code for less. Switch to Opus 4.8 only for cross-repo refactoring needing 400K+ context.

Documentation

Generating README files, API docs, and inline comments. High-volume, repetitive task where cost matters most.

Pick GPT-5.3 Codex: Documentation is high-volume coding work. At $1.75/$14, Codex generates docs at 65% less input cost than Opus 4.8 — ideal for large codebases needing comprehensive docs.

Debugging

Finding and fixing errors in code. Requires reading error traces, understanding logic, and producing targeted fixes.

Pick GPT-5.3 Codex: Purpose-built for code understanding and error resolution. 400K context covers most debugging scenarios at 65% lower input cost than Opus 4.8.

Enterprise Code Analysis

Reviewing entire codebases, cross-module analysis, and architecture decisions. Requires very large context windows.

Pick Claude Opus 4.8: When you need 1M context for full codebase analysis, Opus 4.8's 2.5x larger window is essential. For sub-400K tasks, GPT-5.3 Codex still saves 65% on input.

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Frequently Asked Questions

Is GPT-5.3 Codex better than Claude Opus 4.8 for coding?

GPT-5.3 Codex is purpose-built for coding tasks and costs 65% less on input ($1.75 vs $5 per 1M tokens) and 44% less on output ($14 vs $25). For code generation, debugging, and refactoring, GPT-5.3 Codex typically delivers strong results at a significantly lower price. Claude Opus 4.8 offers a 2.5x larger context window (1M vs 400K) and may excel at complex multi-file reasoning or tasks requiring broad context. For most coding workflows, GPT-5.3 Codex provides better value.

How much can I save switching from Claude Sonnet to GPT-5.3 Codex for coding?

Claude Sonnet (Claude 4 Sonnet) costs $3 input / $15 output per 1M tokens. GPT-5.3 Codex costs $1.75 input / $14 output. That is a 42% saving on input and a 7% saving on output. At 5M input tokens and 2M output tokens per month, you would save $6.25 on input and $2 on output — totaling $8.25/month. At higher volumes the savings scale proportionally.

What is the context window difference between GPT-5.3 Codex and Claude Opus 4.8?

Claude Opus 4.8 has a 1 million token context window, while GPT-5.3 Codex supports 400K tokens. That makes Opus 4.8's context 2.5x larger. For most coding tasks — code generation, debugging, and refactoring of individual files or small modules — 400K is more than sufficient. However, if you need to analyze an entire large codebase in a single prompt, Opus 4.8's 1M context provides a meaningful advantage.

Can GPT-5.3 Codex handle complex enterprise codebases?

GPT-5.3 Codex handles most enterprise coding tasks well within its 400K context window, including code review, refactoring, documentation generation, and debugging. For enterprise workflows that require passing entire monorepos or very large files in a single request, Claude Opus 4.8's 1M context may be preferable. Many teams use both: GPT-5.3 Codex for routine coding tasks at lower cost, and Opus 4.8 for complex cross-file reasoning when the full context is needed.

What is the cheapest coding AI model in 2026?

GPT-5.3 Codex at $1.75 input / $14 output per 1M tokens is one of the cheapest premium coding-focused models. For comparison, Claude Opus 4.8 costs $5/$25, and Claude Sonnet 4.6 costs $3/$15. On the budget end, DeepSeek V4 Pro at $0.435/$0.87 and GPT-5 at $2.50/$10 offer lower prices but are not purpose-built for coding. GPT-5.3 Codex offers the best balance of coding-specific optimization and price.

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