GPT-5.4 Pro vs GPT-5.5

GPT-5.4 Pro (2026) and GPT-5.5 (2026) are frontier-tier reasoning models from OpenAI. Both ship a 1.05m-token context window. On GeneBench-Pro, GPT-5.4 Pro leads by 4.3 pts. On pricing, GPT-5.4 Pro ranges from $30 to $60/1M 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 Pro when coding workflow support matters.

Decision scorecard

Local evidence first
SignalGPT-5.4 ProGPT-5.5
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$30/1M tokens
Provider routes3 tracked4 tracked
Shared benchmarksGeneBench-Pro leader1 shared

Decision tradeoffs

Choose GPT-5.4 Pro when...
  • GPT-5.4 Pro holds a shared-benchmark lead on GeneBench-Pro, ahead by 4.3 points.
  • Local decision data tags GPT-5.4 Pro for Coding, RAG, and Agents.
Choose GPT-5.5 when...
  • GPT-5.5 has the lower cheapest tracked output price at $30/1M tokens.
  • GPT-5.5 has broader tracked provider coverage for fallback and route flexibility.
  • 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.

Lower estimate GPT-5.5

GPT-5.4 Pro

$69,000

Cheapest tracked route/tier: OpenRouter

GPT-5.5

$11,500

Cheapest tracked route/tier: OpenAI API 0-272K input tokens

Estimated monthly gap: $57,500. Batch, cache, alternate speed tiers, and negotiated pricing are excluded from this local estimate.

Switch friction

GPT-5.4 Pro -> GPT-5.5
  • Provider overlap exists on OpenAI API, OpenRouter, and Vercel AI Gateway; start route-level A/B tests there.
  • GPT-5.5 is $150/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
GPT-5.5 -> GPT-5.4 Pro
  • Provider overlap exists on OpenRouter, OpenAI API, and Vercel AI Gateway; start route-level A/B tests there.
  • GPT-5.4 Pro is $150/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.

Specs

Specification
Released2026-03-012026-04-23
Context window1.05m1.05m
Parameters——
ArchitectureDecoder OnlyDecoder Only
LicenseProprietaryProprietary
OpennessProprietaryProprietary
WeightsNot releasedNot released
CodeUnknownUnknown
Commercial useCommercial use: conditionalCommercial use: conditional
Knowledge cutoff2025-082025-12

Pricing and availability

Pricing attributeGPT-5.4 ProGPT-5.5
Input price
0-272,000t
$30/1M tokens
272,000t+
$60/1M tokens
0-272K input tokens
$5/1M tokens
Standard GPT-5.5 token pricing before the long-context surcharge threshold.
272K+ input tokens
$8/1M tokens
Long-context surcharge applies above 272K input tokens for the full session.
Output price
0-272,000t
$180/1M tokens
272,000t+
$270/1M tokens
0-272K input tokens
$30/1M tokens
Standard GPT-5.5 token pricing before the long-context surcharge threshold.
272K+ input tokens
$36/1M tokens
Long-context surcharge applies above 272K input tokens for the full session.
Providers
OpenRouterOpenAI APIVercel AI Gateway
OpenAI APIOpenRouterVercel AI GatewayAWS Bedrock

Capabilities

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

Benchmarks

BenchmarkGPT-5.4 ProGPT-5.5
GeneBench-Pro16.312.0

Continue comparing

Model pages
Labs and families
Related comparisons

Popular comparisons for GPT-5.4 Pro

Popular comparisons for GPT-5.5

Last reviewed: 2026-10-07. Data sourced from public model cards and provider documentation.