Claude Haiku 4.5 vs GPT-5.3-Codex
Claude Haiku 4.5 (2025) and GPT-5.3-Codex (2026) compare a standalone API model against a coding-specialized model. Claude Haiku 4.5 ships a 200k-token context window, while GPT-5.3-Codex ships a 400k-token context window. On SWE-bench Verified, GPT-5.3-Codex leads by 11.7 pts. On pricing, Claude Haiku 4.5 costs $0.80/1M input tokens versus $1.75/1M for the alternative. This page treats the result as workflow and deployment fit, not a universal model winner.
Treat this as a product-type comparison: Claude Haiku 4.5 is standalone API model, while GPT-5.3-Codex is coding-specialized model. Choose based on workflow fit before reading any benchmark or price row as decisive.
Decision scorecard
Local evidence first| Signal | Claude Haiku 4.5 | GPT-5.3-Codex |
|---|---|---|
| Product type | Standalone API model | Coding-specialized model |
| Best for | multimodal apps, tool-calling agents, and provider-routed production | custom coding agents, code generation, and tool loops |
| Decision fit | Coding, RAG, and Agents | Coding, RAG, and Agents |
| Context window | 200k | 400k |
| Cheapest output | $4/1M tokens | $14/1M tokens |
| Provider routes | 9 tracked | 3 tracked |
| Shared benchmarks | 1 shared | SWE-bench Verified leader |
Decision tradeoffs
- Claude Haiku 4.5 has the lower cheapest tracked output price at $4/1M tokens.
- Claude Haiku 4.5 has broader tracked provider coverage for fallback and route flexibility.
- Claude Haiku 4.5 uniquely exposes Multimodal in local model data.
- Local decision data tags Claude Haiku 4.5 for Coding, RAG, and Agents.
- GPT-5.3-Codex holds a shared-benchmark lead on SWE-bench Verified, ahead by 11.7 points.
- GPT-5.3-Codex has the larger context window for long prompts, retrieval packs, or transcript analysis.
- GPT-5.3-Codex uniquely exposes Reasoning and Computer use in local model data.
- Local decision data tags GPT-5.3-Codex for Coding, RAG, and Agents.
Monthly cost at traffic
Estimate token spend from the cheapest tracked input and output route or tier on this page.
Claude Haiku 4.5
$1,640
Cheapest tracked route/tier: AWS Bedrock
GPT-5.3-Codex
$4,900
Cheapest tracked route/tier: OpenRouter
Estimated monthly gap: $3,260. Batch, cache, alternate speed tiers, and negotiated pricing are excluded from this local estimate.
Switch friction
- Provider overlap exists on OpenRouter and Vercel AI Gateway; start route-level A/B tests there.
- GPT-5.3-Codex is $10/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
- Check replacement coverage for Multimodal before moving production traffic.
- GPT-5.3-Codex adds Reasoning and Computer use in local capability data.
- Provider overlap exists on OpenRouter and Vercel AI Gateway; start route-level A/B tests there.
- Claude Haiku 4.5 is $10/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
- Check replacement coverage for Reasoning and Computer use before moving production traffic.
- Claude Haiku 4.5 adds Multimodal in local capability data.
Specs
| Specification | ||
|---|---|---|
| Released | 2025-10-01 | 2026-02-05 |
| Context window | 200k | 400k |
| Parameters | — | — |
| Architecture | Decoder Only | Decoder Only |
| License | Proprietary | Proprietary |
| Openness | Proprietary | Proprietary |
| Weights | Not released | Not released |
| Code | Unknown | Unknown |
| Commercial use | Commercial use: conditional | Commercial use: conditional |
| Knowledge cutoff | 2025-02 | 2025-08 |
Pricing and availability
| Pricing attribute | Claude Haiku 4.5 | GPT-5.3-Codex |
|---|---|---|
| Input price | $0.80/1M tokens | $1.75/1M tokens |
| Output price | $4/1M tokens | $14/1M tokens |
| Providers |
Capabilities
| Capability | Claude Haiku 4.5 | GPT-5.3-Codex |
|---|---|---|
| Vision | Yes | Yes |
| Multimodal | Yes | No |
| Reasoning | No | Yes |
| JSON / Tool use | Yes | Yes |
| Structured outputs | Yes | Yes |
| Code execution | Yes | Yes |
| IDE integration | No | No |
| Computer use | No | Yes |
| Parallel agents | No | No |
Benchmarks
| Benchmark | Claude Haiku 4.5 | GPT-5.3-Codex |
|---|---|---|
| SWE-bench Verified | 73.3 | 85.0 |
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Last reviewed: 2026-07-26. Data sourced from public model cards and provider documentation.