GPT-5 vs GPT-5.5 Pro
GPT-5 (2025) and GPT-5.5 Pro (2026) are frontier-tier reasoning models from OpenAI. GPT-5 ships a 400k-token context window, while GPT-5.5 Pro ships a 1.05m-token context window. On SWE-bench Verified, GPT-5.5 Pro leads by 7.7 pts. On pricing, GPT-5 costs $1.25/1M input tokens versus $30/1M for the alternative. This comparison covers specs, pricing, API access, capabilities, benchmarks, input and output token costs, and production fit for coding and agent workloads.
GPT-5 is ~2300% cheaper at $1.25/1M; pay for GPT-5.5 Pro only for coding workflow support.
Decision scorecard
Local evidence first| Signal | GPT-5 | GPT-5.5 Pro |
|---|---|---|
| Best for | reasoning-heavy apps, multimodal apps, and tool-calling agents | reasoning-heavy apps, multimodal apps, and tool-calling agents |
| Decision fit | Coding, RAG, and Agents | Coding, RAG, and Agents |
| Context window | 400k | 1.05m |
| Cheapest output | $10/1M tokens | $180/1M tokens |
| Provider routes | 4 tracked | 3 tracked |
| Shared benchmarks | 2 shared | SWE-bench Verified leader |
Decision tradeoffs
- GPT-5 has the lower cheapest tracked output price at $10/1M tokens.
- GPT-5 has broader tracked provider coverage for fallback and route flexibility.
- Local decision data tags GPT-5 for Coding, RAG, and Agents.
- GPT-5.5 Pro holds a shared-benchmark lead on SWE-bench Verified, ahead by 7.7 points.
- GPT-5.5 Pro has the larger context window for long prompts, retrieval packs, or transcript analysis.
- Local decision data tags GPT-5.5 Pro 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.
GPT-5
$3,500
Cheapest tracked route/tier: Replicate API
GPT-5.5 Pro
$69,000
Cheapest tracked route/tier: OpenAI API <=272K tokens (standard)
Estimated monthly gap: $65,500. Batch, cache, alternate speed tiers, and negotiated pricing are excluded from this local estimate.
Switch friction
- Provider overlap exists on OpenAI API, OpenRouter, and Vercel AI Gateway; start route-level A/B tests there.
- GPT-5.5 Pro is $170/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
- Provider overlap exists on OpenRouter, OpenAI API, and Vercel AI Gateway; start route-level A/B tests there.
- GPT-5 is $170/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
Specs
| Specification | ||
|---|---|---|
| Released | 2025-08-07 | 2026-04-23 |
| Context window | 400k | 1.05m |
| 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 | 2024-09 | 2025-12 |
Pricing and availability
| Pricing attribute | GPT-5 | GPT-5.5 Pro |
|---|---|---|
| Input price | $1.25/1M tokens | $30/1M tokens |
| Output price | $10/1M tokens | $180/1M tokens |
| Providers |
Capabilities
| Capability | GPT-5 | GPT-5.5 Pro |
|---|---|---|
| Vision | Yes | Yes |
| Multimodal | Yes | Yes |
| Reasoning | Yes | Yes |
| JSON / Tool use | Yes | Yes |
| Structured outputs | Yes | Yes |
| Code execution | Yes | Yes |
| IDE integration | No | No |
| Computer use | No | No |
| Parallel agents | No | No |
Benchmarks
| Benchmark | GPT-5 | GPT-5.5 Pro |
|---|---|---|
| SWE-bench Verified | 74.9 | 82.6 |
| Google-Proof Q&A | 88.4 | 93.6 |
Continue comparing
Popular comparisons for GPT-5
Popular comparisons for GPT-5.5 Pro
Last reviewed: 2026-06-29. Data sourced from public model cards and provider documentation.