GPT-5.4 vs GPT-5.5
GPT-5.4 (2026) and GPT-5.5 (2026) are frontier-tier reasoning models from OpenAI. GPT-5.4 ships a 1.05m-token context window, while GPT-5.5 ships a 1.05m-token context window. On MMLU PRO, GPT-5.5 leads by 0.6 pts. On pricing, GPT-5.4 ranges from $2.50 to $5/1M input tokens by tier; GPT-5.5 ranges from $5 to $8/1M input tokens by tier. This comparison covers specs, pricing, API access, capabilities, benchmarks, input and output token costs, and production fit for coding and agent workloads.
GPT-5.5 is safer overall; choose GPT-5.4 when coding workflow support matters.
Decision scorecard
Local evidence first| Signal | GPT-5.4 | GPT-5.5 |
|---|---|---|
| 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 | 1.05m | 1.05m |
| Cheapest output | $15/1M tokens | $30/1M tokens |
| Provider routes | 4 tracked | 4 tracked |
| Shared benchmarks | 10 shared | MMLU PRO leader |
Decision tradeoffs
- GPT-5.4 holds a shared-benchmark lead on Humanity's Last Exam, ahead by 0.2 points.
- GPT-5.4 has the lower cheapest tracked output price at $15/1M tokens.
- Local decision data tags GPT-5.4 for Coding, RAG, and Agents.
- GPT-5.5 holds a shared-benchmark lead on MMLU PRO, ahead by 0.6 points.
- Local decision data tags GPT-5.5 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-5.4
$5,750
Cheapest tracked route/tier: OpenAI API
GPT-5.5
$11,500
Cheapest tracked route/tier: OpenAI API 0-272K input tokens
Estimated monthly gap: $5,750. 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 is $15/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
- Provider overlap exists on OpenAI API, OpenRouter, and Vercel AI Gateway; start route-level A/B tests there.
- GPT-5.4 is $15/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
Specs
| Specification | ||
|---|---|---|
| Released | 2026-03-05 | 2026-04-23 |
| Context window | 1.05m | 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 | 2025-08 | 2025-12 |
Pricing and availability
| Pricing attribute | GPT-5.4 | GPT-5.5 |
|---|---|---|
| Input price |
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| Output price |
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| Providers |
Capabilities
| Capability | GPT-5.4 | GPT-5.5 |
|---|---|---|
| Vision | Yes | Yes |
| Multimodal | Yes | Yes |
| Reasoning | Yes | Yes |
| Function calling | Yes | Yes |
| 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-5.4 | GPT-5.5 |
|---|---|---|
| MMLU PRO | 87.5 | 88.1 |
| SWE-bench Verified | 71.7 | 82.6 |
| SWE-bench Pro | 57.7 | 58.6 |
| Google-Proof Q&A | 92.0 | 93.6 |
| Humanity's Last Exam | 41.6 | 41.4 |
| ARC-AGI-2 | 73.3 | 85.0 |
| Chatbot Arena | 1479.0 | 1488.0 |
| Terminal-Bench 2.0 | 75.1 | 82.7 |
| MMMU Pro | 81.2 | 88.3 |
| GeneBench-Pro | 8.9 | 12.0 |
Deep dive
On shared benchmark coverage, MMLU PRO has GPT-5.4 at 87.5 and GPT-5.5 at 88.1, with GPT-5.5 ahead by 0.6 points; SWE-bench Verified has GPT-5.4 at 71.7 and GPT-5.5 at 82.6, with GPT-5.5 ahead by 10.9 points; SWE-bench Pro has GPT-5.4 at 57.7 and GPT-5.5 at 58.6, with GPT-5.5 ahead by 0.9 points. The largest visible gap is 10.9 points on SWE-bench Verified, which matters most when that benchmark mirrors your workload. Treat isolated benchmark wins as directional, because provider routing, prompt style, and tool access can move real application results.
The capability footprint is close: both models cover vision, multimodal input, reasoning mode, function calling, and tool use. That makes context budget, benchmark fit, and provider maturity more important than a simple checklist. If your application depends on one integration detail, verify it against the provider route you plan to use, not just the base model listing.
For cost, GPT-5.4 lists tiered pricing: 0-272,000t is $2.50/1M input and $15/1M output; 272,000t+ is $5/1M input and $22.50/1M output, while GPT-5.5 lists tiered pricing: 0-272K input tokens is $5/1M input and $30/1M output; 272K+ input tokens is $8/1M input and $36/1M output. A 70/30 input-output blend puts GPT-5.4 lower by about $6.25 per million blended tokens. For tiered rows, this cheapest-track view can understate interactive or fast-lane spend, so compare the tier you will actually use. Availability is 4 providers versus 4, so concentration risk also matters.
Choose GPT-5.4 when coding workflow support and lower cheapest-tier input-token cost are central to the workload. Choose GPT-5.5 when coding workflow support are more important. For production, rerun your own prompts through the exact provider, region, and tool stack you plan to ship.
FAQ
Which has a larger context window, GPT-5.4 or GPT-5.5?
GPT-5.4 supports 1.05m tokens, while GPT-5.5 supports 1.05m tokens. That gap matters most for long documents, large codebases, retrieval-heavy agents, and conversations where earlier context must remain visible. Use this as a quick comparison signal, then confirm the provider-specific limits before committing to production.
Which is cheaper, GPT-5.4 or GPT-5.5?
GPT-5.4 lists tiered pricing: 0-272,000t is $2.50/1M input and $15/1M output; 272,000t+ is $5/1M input and $22.50/1M output. GPT-5.5 lists tiered pricing: 0-272K input tokens is $5/1M input and $30/1M output; 272K+ input tokens is $8/1M input and $36/1M output. Compare the tier you will actually use; cheap async pricing can overstate savings for interactive workflows. Provider discounts or batch pricing can still change the final bill.
Is GPT-5.4 or GPT-5.5 open source?
GPT-5.4 is listed under Proprietary. GPT-5.5 is listed under Proprietary. License labels affect whether you can self-host, redistribute weights, or rely only on hosted APIs, so confirm the upstream license before deployment.
Which is better for vision, GPT-5.4 or GPT-5.5?
Both GPT-5.4 and GPT-5.5 expose vision. The better choice depends on benchmark fit, context budget, pricing, and whether your provider route exposes the same capability surface. Use this as a quick comparison signal, then confirm the provider-specific limits before committing to production.
Which is better for multimodal input, GPT-5.4 or GPT-5.5?
Both GPT-5.4 and GPT-5.5 expose multimodal input. The better choice depends on benchmark fit, context budget, pricing, and whether your provider route exposes the same capability surface. Use this as a quick comparison signal, then confirm the provider-specific limits before committing to production.
Where can I run GPT-5.4 and GPT-5.5?
GPT-5.4 is available on OpenAI API, OpenRouter, Vercel AI Gateway, and AWS Bedrock. GPT-5.5 is available on OpenAI API, OpenRouter, Vercel AI Gateway, and AWS Bedrock. Provider coverage can affect latency, region availability, compliance posture, and fallback options.
Continue comparing
Popular comparisons for GPT-5.4
Popular comparisons for GPT-5.5
Last reviewed: 2026-06-29. Data sourced from public model cards and provider documentation.