Claude Sonnet 5 vs GPT-5.3 Codex
Pricing verdict: Claude Sonnet 5 vs GPT-5.3 Codex: GPT-5.3 Codex is cheaper for input-heavy usage ($1.75/M vs $2.00/M input tokens), while Claude Sonnet 5 is better for long-context tasks (1,000,000 tokens).
Direct answer: choose GPT-5.3 Codex for lower token spend and choose Claude Sonnet 5 when your workload needs longer context.
Compare API pricing, input and output token costs, context windows, and monthly estimates on one page so you can pick the right model fast.
Cost Comparison (1000 input + 500 output tokens, 100 requests/day)
Claude Sonnet 5
GPT-5.3 Codex
Cost Differences
GPT-5.3 Codex costs more than Claude Sonnet 5
Quick Recommendation
Winner for direct API pricing: Claude Sonnet 5. At the default workload, Claude Sonnet 5 saves about $5.25/month ($63.875/year) versus GPT-5.3 Codex.
Feature Comparison
| Feature | Claude Sonnet 5 | GPT-5.3 Codex |
|---|---|---|
| Provider | Anthropic | OpenAI |
| Input Price | $2.00/1M tokens | $1.75/1M tokens |
| Output Price | $10.00/1M tokens | $14.00/1M tokens |
| Context Window | 1,000,000 tokens | 256,000 tokens |
| Max Output | 128,000 tokens | 32,768 tokens |
| Category | balanced | coding |
| Capabilities | textvisioncodereasoningcomputer-use | textcode |
| Release Date | 6/30/2026 | 3/1/2026 |
Claude Sonnet 5 vs GPT-5.3 Codex: Which Should You Choose?
Choosing between Claude Sonnet 5 and GPT-5.3 Codex depends on your priorities: cost efficiency, context length, or raw capability. GPT-5.3 Codex is the more affordable option at $1.75/1M input tokens — 13% cheaper than Claude Sonnet 5. Meanwhile, Claude Sonnet 5 offers a significantly larger context window at 1,000,000 tokens vs 256,000 for GPT-5.3 Codex.
These models come from different providers — Anthropic and OpenAI — which means different API ecosystems, SDKs, rate limits, and terms of service. If you're already integrated with Anthropic, switching to OpenAIinvolves migration effort beyond just pricing. Factor in your existing infrastructure when deciding.
These models target different tiers: Claude Sonnet 5 is a balanced model while GPT-5.3 Codex is coding. This means they're optimized for different workloads. GPT-5.3 Codex targets more demanding workloads, while Claude Sonnet 5 provides a cost-effective option for everyday tasks.
Output costs matter too. Claude Sonnet 5 charges $10.00/1M output tokens vs $14.00 for GPT-5.3 Codex. For generation-heavy workloads (content creation, code generation, summarization), output pricing often dominates your bill. Claude Sonnet 5 has the edge here at $10.00/1M output tokens.
Multimodal capabilities: Claude Sonnet 5 supports vision (image inputs) while GPT-5.3 Codex is text-only. If your application needs image understanding, this narrows your choice.
Best Use Cases
Choose Claude Sonnet 5 when:
- • You need a larger context window (1,000,000 tokens)
- • You need more capabilities (vision, reasoning, computer-use)
- • You need longer outputs (up to 128,000 tokens)
- • You're already using Anthropic's API ecosystem
Choose GPT-5.3 Codex when:
- • Budget is a primary concern
- • You're already using OpenAI's API ecosystem
Pros and Caveats at a Glance
Claude Sonnet 5
- • Input pricing: $2.00/M tokens
- • Output pricing: $10.00/M tokens
- • Context window: 1,000,000 tokens
- • Max output: 128,000 tokens
Watch out for
- • Higher input cost than GPT-5.3 Codex
GPT-5.3 Codex
- • Input pricing: $1.75/M tokens
- • Output pricing: $14.00/M tokens
- • Context window: 256,000 tokens
- • Max output: 32,768 tokens
Watch out for
- • Higher output cost than Claude Sonnet 5
- • Smaller context window than Claude Sonnet 5
Try Different Scenarios
Use the calculator below to see how costs change with different usage patterns
Claude Sonnet 5 (Anthropic)
GPT-5.3 Codex (OpenAI)
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Which is cheaper, Claude Sonnet 5 or GPT-5.3 Codex?▼
What is the context window difference between Claude Sonnet 5 and GPT-5.3 Codex?▼
Which model is better for AI Chatbot?▼
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Where can I compare Anthropic and OpenAI API pricing beyond this model matchup?▼
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