LLM Reference

GPT-5.4 Pro vs GPT-5.5 Pro

GPT-5.4 Pro (2026) and GPT-5.5 Pro (2026) are frontier-tier reasoning models from OpenAI. GPT-5.4 Pro ships a 1.05m-token context window, while GPT-5.5 Pro ships a 1.05m-token context window. On pricing, GPT-5.4 Pro ranges from $30 to $60/1M input tokens by tier; GPT-5.5 Pro ranges from $30 to $60/1M 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 Pro is safer overall; choose GPT-5.4 Pro when coding workflow support matters.

Decision scorecard

Local evidence first
SignalGPT-5.4 ProGPT-5.5 Pro
Best forreasoning-heavy apps, multimodal apps, and tool-calling agentsreasoning-heavy apps, multimodal apps, and tool-calling agents
Decision fitCoding, RAG, and AgentsCoding, RAG, and Agents
Context window1.05m1.05m
Cheapest output$180/1M tokens$180/1M tokens
Provider routes3 tracked3 tracked
Shared benchmarks0 rows0 rows

Decision tradeoffs

Choose GPT-5.4 Pro when...
  • Local decision data tags GPT-5.4 Pro for Coding, RAG, and Agents.
Choose GPT-5.5 Pro when...
  • 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.

Same estimate Tie

GPT-5.4 Pro

$69,000

Cheapest tracked route/tier: OpenRouter

GPT-5.5 Pro

$69,000

Cheapest tracked route/tier: OpenAI API

Estimated monthly gap: $0.00. Batch, cache, alternate speed tiers, and negotiated pricing are excluded from this local estimate.

Switch friction

GPT-5.4 Pro -> GPT-5.5 Pro
  • Provider overlap exists on OpenAI API, OpenRouter, and Vercel AI Gateway; start route-level A/B tests there.
  • Cheapest tracked output pricing is tied, so migration risk shifts to quality, latency, and provider packaging.
GPT-5.5 Pro -> GPT-5.4 Pro
  • Provider overlap exists on OpenRouter, OpenAI API, and Vercel AI Gateway; start route-level A/B tests there.
  • Cheapest tracked output pricing is tied, so migration risk shifts to quality, latency, and provider packaging.

Specs

Specification
Released2026-03-012026-04-23
Context window1.05m1.05m
Parameters
Architecturedecoder onlydecoder only
LicenseProprietaryProprietary
OpennessProprietaryProprietary
Commercial useCommercial use with conditionsCommercial use with conditions
Knowledge cutoff2025-082025-12

Pricing and availability

Pricing attributeGPT-5.4 ProGPT-5.5 Pro
Input price
0-272,000t
$30/1M tokens
272,000t+
$60/1M tokens
0-272,000t
$30/1M tokens
272,000t+
$60/1M tokens
Output price
0-272,000t
$180/1M tokens
272,000t+
$270/1M tokens
0-272,000t
$180/1M tokens
272,000t+
$270/1M tokens
Providers

Capabilities

CapabilityGPT-5.4 ProGPT-5.5 Pro
VisionYesYes
MultimodalYesYes
ReasoningYesYes
Function callingYesYes
Tool useYesYes
Structured outputsYesYes
Code executionYesYes
IDE integrationNoNo
Computer useNoNo
Parallel agentsNoNo

Benchmarks

No shared benchmark rows are currently sourced for this pair.

Deep dive

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 Pro lists tiered pricing: 0-272,000t is $30/1M input and $180/1M output; 272,000t+ is $60/1M input and $270/1M output, while GPT-5.5 Pro lists tiered pricing: 0-272,000t is $30/1M input and $180/1M output; 272,000t+ is $60/1M input and $270/1M output. A 70/30 input-output blend is tied on the cheapest tracked routes. For tiered rows, this cheapest-track view can understate interactive or fast-lane spend, so compare the tier you will actually use. Availability is 3 providers versus 3, so concentration risk also matters.

Choose GPT-5.4 Pro when coding workflow support are central to the workload. Choose GPT-5.5 Pro 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 Pro or GPT-5.5 Pro?

GPT-5.4 Pro supports 1.05m tokens, while GPT-5.5 Pro supports 1.05m tokens. That gap matters most for long documents, large codebases, retrieval-heavy agents, and conversations where earlier context must remain visible.

Which is cheaper, GPT-5.4 Pro or GPT-5.5 Pro?

Neither is cheaper on tracked token pricing. Both list $30/1M input and $180/1M output tokens on the cheapest tracked route. Provider discounts, batch pricing, or route-specific tiers can still change the final bill.

Is GPT-5.4 Pro or GPT-5.5 Pro open source?

GPT-5.4 Pro is listed under Proprietary. GPT-5.5 Pro 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 Pro or GPT-5.5 Pro?

Both GPT-5.4 Pro and GPT-5.5 Pro 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 Pro or GPT-5.5 Pro?

Both GPT-5.4 Pro and GPT-5.5 Pro 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 Pro and GPT-5.5 Pro?

GPT-5.4 Pro is available on OpenRouter, OpenAI API, and Vercel AI Gateway. GPT-5.5 Pro is available on OpenAI API, OpenRouter, and Vercel AI Gateway. Provider coverage can affect latency, region availability, compliance posture, and fallback options.

Continue comparing

Last reviewed: 2026-05-22. Data sourced from public model cards and provider documentation.