Agentic
Directional only- GPT-5.4 Pro
- 58.1
- Estimated · #33/151
- GPT-5.5 Pro
- 60.6
- Estimated · #24/151
- Basis
- BenchAlign lane · 1 vs 1 public rows
- Reading
- Directional only
GPT-5.4 Pro vs GPT-5.5 Pro
Updated September 4, 2026. Public scores include evidence status and uncertainty. They are not guarantees for a specific workload.
Decision reading
GPT-5.5 Pro has the higher public score estimate, 63.07 versus 61.75, but the 90% score intervals overlap. Treat that as a lead, not a settled winner.
6 results are shared. Category rows resting on Estimated evidence or different benchmark sets are marked directional and do not name a winner.
Share or export
Which one for your work
Recommendations appear only when a shared evidence basis or an explicit operating constraint supports the call. Secondary and unsupported use cases stay disclosed below the initial list.
No workload recommendation clears the current evidence threshold.
Use the matched evidence, workload costs, and sourced specifications below instead of treating a point score as a universal answer.
Show secondary and unsupported calls
Coding work
Code generation, repair, and software-engineering tasks
Not enough matched evidence
GPT-5.4 Pro and GPT-5.5 Pro are not ranked on the public lane for coding, so no winner is named for coding.
Confidence: limited
Agentic work
Tool use, computer use, and multi-step task completion
Not enough matched evidence
GPT-5.4 Pro and GPT-5.5 Pro are scored on Estimated evidence for agentic, so the reading is directional rather than like-for-like.
Confidence: limited
Long documents
Prompts that approach the documented context limit
No clear pick
The documented context windows are equal.
Confidence: documented
Chat turn cost
1K fresh input + 500 output tokens
No clear pick
A complete comparable API-rate estimate is not available for both models.
Confidence: listed-rates
Cache-heavy agent loop cost
200K cached + 20K fresh input + 10K output tokens
No clear pick
A complete comparable API-rate estimate is not available for both models.
Confidence: rate-fallback
Repository review cost
50K fresh input + 3K output tokens
No clear pick
A complete comparable API-rate estimate is not available for both models.
Confidence: listed-rates
What is actually comparable
Shared results can support a head-to-head reading. Results present for only one model describe coverage, not superiority.
4 GPT-5.4 Pro only
6 Shared
- Shared results
- 6
- GPT-5.4 Pro only
- 4
- GPT-5.5 Pro only
- 0
- Like-for-like categories
- 0 / 8
2 categories rest on Estimated evidence or different evidence sets. Those rows remain visible for coverage context but do not name a winner.
Category results, on a stated basis
Each row shows the public-lane category score for both models: the BenchAlign lane for agentic, coding, and knowledge, and the weighted public rows elsewhere, with the same rank each model page reports. A row is like-for-like only when both scores rest on Supported evidence or the same weighted set. Directional and not-comparable rows remain visible, but they never receive a winner.
Knowledge
Directional only- GPT-5.4 Pro
- 60.7
- Estimated · #39/181
- GPT-5.5 Pro
- 61.1
- Estimated · #36/181
- Basis
- BenchAlign lane · 4 vs 2 public rows
- Reading
- Directional only
Coding
Not comparable- GPT-5.4 Pro
- Not ranked
- GPT-5.5 Pro
- Not ranked
- Basis
- BenchAlign lane · 0 vs 0 public rows
- Reading
- Not comparable
Reasoning
Not comparable- GPT-5.4 Pro
- 70.1
- Unranked · 2 rankable rows
- GPT-5.5 Pro
- Not ranked
- Basis
- Provisional lane · 1 vs 0 weighted rows
- Reading
- Not comparable
Math
Not comparable- GPT-5.4 Pro
- 69.0
- Unranked · 4 rankable rows
- GPT-5.5 Pro
- 70.2
- Unranked · 3 rankable rows
- Basis
- Provisional lane · 2 vs 2 weighted rows
- Reading
- Not comparable
Multilingual
Not comparable- GPT-5.4 Pro
- Not ranked
- GPT-5.5 Pro
- Not ranked
- Basis
- Provisional lane · 0 vs 0 weighted rows
- Reading
- Not comparable
Multimodal
Not comparable- GPT-5.4 Pro
- Not ranked
- GPT-5.5 Pro
- Not ranked
- Basis
- Provisional lane · 0 vs 0 weighted rows
- Reading
- Not comparable
Instruction following
Not comparable- GPT-5.4 Pro
- Not ranked
- GPT-5.5 Pro
- Not ranked
- Basis
- Provisional lane · 0 vs 0 weighted rows
- Reading
- Not comparable
| Category | GPT-5.4 Pro | GPT-5.5 Pro | Basis | Reading |
|---|---|---|---|---|
| Agentic | 58.1Estimated · #33/151 | 60.6Estimated · #24/151 | Directional onlyBenchAlign lane · 1 vs 1 public rows | Directional only |
| Knowledge | 60.7Estimated · #39/181 | 61.1Estimated · #36/181 | Directional onlyBenchAlign lane · 4 vs 2 public rows | Directional only |
| Coding | Not ranked | Not ranked | Not comparableBenchAlign lane · 0 vs 0 public rows | Not comparable |
| Reasoning | 70.1Unranked · 2 rankable rows | Not ranked | Not comparableProvisional lane · 1 vs 0 weighted rows | Not comparable |
| Math | 69.0Unranked · 4 rankable rows | 70.2Unranked · 3 rankable rows | Not comparableProvisional lane · 2 vs 2 weighted rows | Not comparable |
| Multilingual | Not ranked | Not ranked | Not comparableProvisional lane · 0 vs 0 weighted rows | Not comparable |
| Multimodal | Not ranked | Not ranked | Not comparableProvisional lane · 0 vs 0 weighted rows | Not comparable |
| Instruction following | Not ranked | Not ranked | Not comparableProvisional lane · 0 vs 0 weighted rows | Not comparable |
Ranks count the models scored in each category’s lane, so the agentic, coding, and knowledge denominators (BenchAlign) differ from the provisional-lane categories. Unranked scores sit on the lane’s scale but never name a winner. Like-for-like rows within 0.5 points read as a practical tie.
Shape of the matched evidence
Only shared public evidence is shown. Sparse evidence stays a ruled list rather than being closed into a radar shape.
Too few matched category axes support a radar. The ruled list below shows only shared benchmark results; positions use each benchmark’s normalized display scale when available.
FrontierMath v2 (Tier 4)
Math
HLE
Knowledge
FrontierMath v2 (Tiers 1-3)
Math
BrowseComp
Agentic
HLE w/o tools
Knowledge
What each workload costs
Three fixed token mixes turn per-token rates into comparable decisions. Each scenario states context fit and whether cached input had to fall back to the published list-input rate.
Chat turn
1K fresh input + 500 output tokens
- GPT-5.4 Pro
- $0.12
- Fits in one request
- GPT-5.5 Pro
- $0.12
- Fits in one request
Modeled costs are equal
Costs use the listed standard API rates.
Repository review
50K fresh input + 3K output tokens
- GPT-5.4 Pro
- $2.04
- Fits in one request
- GPT-5.5 Pro
- $2.04
- Fits in one request
Modeled costs are equal
Costs use the listed standard API rates.
Cache-heavy agent loop
200K cached + 20K fresh input + 10K output tokens
- GPT-5.4 Pro
- $8.40
- Fits in one request
- Cached input priced at the published list-input rate
- GPT-5.5 Pro
- $8.40
- Fits in one request
- Cached input priced at the published list-input rate
Modeled costs are equal
GPT-5.4 Pro has no published cached-input rate, so cached tokens use its listed input rate. GPT-5.5 Pro has no published cached-input rate, so cached tokens use its listed input rate.
Specification differences
Sourced differences are shown directly. Missing facts stay explicit instead of being inferred from a model name or family.
SpecificationGPT-5.4 ProGPT-5.5 Pro
Context window
Maximum documented context; output-token limits may be lower.
GPT-5.4 Pro
GPT-5.5 Pro
API model ID
GPT-5.4 Pro
gpt-5.4-pro
OpenAI GPT-5.4 Pro model documentationGPT-5.5 Pro
gpt-5.5-pro
OpenAI GPT-5.5 Pro model documentationCached-input rate
A missing cached-input rate falls back to the listed input rate only in the stated workload estimate.
GPT-5.4 Pro
Not published
OpenAI pricingGPT-5.5 Pro
Not published
OpenAI pricingDocumented inputs
GPT-5.4 Pro
text, image
OpenAI model catalogGPT-5.5 Pro
text, image
OpenAI model catalogDocumented outputs
GPT-5.4 Pro
GPT-5.5 Pro
Provider availability
GPT-5.4 Pro
Generally Available · OpenAI Responses API
OpenAI model catalogGPT-5.5 Pro
Generally Available · OpenAI Responses API
OpenAI model catalogReasoning profile
GPT-5.4 Pro
Reasoning
GPT-5.5 Pro
Reasoning
Weight access
GPT-5.4 Pro
Proprietary
GPT-5.5 Pro
Proprietary
License
GPT-5.4 Pro
Proprietary
GPT-5.5 Pro
Proprietary
Release date
GPT-5.4 Pro
2026-03-05
GPT-5.5 Pro
2026-04-23
If you already use one of these models
- Deployment change
- Both entries list OpenAI as the provider. Confirm endpoint, model ID, limits, and feature support before switching.
- Quality signal
- GPT-5.5 Pro has the higher public score estimate, 63.07 versus 61.75, but the 90% score intervals overlap.
- Workload cost
- Repository review: $2.04 vs $2.04. Cache-heavy agent loop: $8.40 vs $8.40.
- Context tradeoff
- Both models list 1.05M.
Run the same representative tasks against both endpoints before changing production traffic.
Benchmark evidence
The full public result ledger is available for audit without forcing a wide desktop table onto a phone.
Browse raw public benchmark evidence10 rows
Agentic
Reasoning
ARC-AGI-2
GPT-5.4 Pro83.3%SourceGPT-5.5 Pro—Not directly comparable
Knowledge
HLE
GPT-5.4 Pro58.7%SourceGPT-5.5 Pro57.2%SourceGPT-5.4 Pro leads this result
FrontierScience
GPT-5.4 Pro36.7%SourceGPT-5.5 Pro—Not directly comparable
FrontierScience Research
GPT-5.4 Pro36.7%SourceGPT-5.5 Pro—Not directly comparable
HLE w/o tools
GPT-5.4 Pro42.7%SourceGPT-5.5 Pro43.1%SourceGPT-5.5 Pro leads this result
Math
IPhO 2025 (Theory)
GPT-5.4 Pro93.5%SourceGPT-5.5 Pro—Not directly comparable
FrontierMath (legacy)
GPT-5.4 Pro50%SourceGPT-5.5 Pro52.4%SourceGPT-5.5 Pro leads this result
FrontierMath v2 (Tiers 1-3)
Shared sourceGPT-5.4 Pro50.000%GPT-5.5 Pro51.000%GPT-5.5 Pro leads this result
FrontierMath v2 (Tier 4)
Shared sourceGPT-5.4 Pro37.500%GPT-5.5 Pro39.600%GPT-5.5 Pro leads this result
Frequently asked questions
Which is better, GPT-5.4 Pro or GPT-5.5 Pro?
GPT-5.5 Pro has the higher public score estimate, 63.07 versus 61.75, but the 90% score intervals overlap. The higher estimate is not a decisive winner because the uncertainty ranges overlap.
Which is better for coding, GPT-5.4 Pro or GPT-5.5 Pro?
GPT-5.4 Pro and GPT-5.5 Pro are not ranked on the public lane for coding, so no winner is named for coding.
Which is better for agentic tasks, GPT-5.4 Pro or GPT-5.5 Pro?
GPT-5.5 Pro scores higher for agentic tasks on the public lane, 60.6 to 58.1. GPT-5.4 Pro and GPT-5.5 Pro are scored on Estimated evidence for agentic tasks, so the reading is directional rather than like-for-like. BenchLM does not name a winner for agentic tasks from a directional reading; read the shared benchmark rows directly and test the models on the same task set.
Which costs less, GPT-5.4 Pro or GPT-5.5 Pro?
For the stated presets, chat costs $0.12 on GPT-5.4 Pro and $0.12 on GPT-5.5 Pro; repository review costs $2.04 and $2.04; the cache-heavy agent loop costs $8.40 and $8.40. GPT-5.4 Pro has no published cached-input rate, so cached tokens use its listed input rate. GPT-5.5 Pro has no published cached-input rate, so cached tokens use its listed input rate.
Which has the larger context window, GPT-5.4 Pro or GPT-5.5 Pro?
Both models list the same context window, 1.05M.
Related comparisons
Last updated September 4, 2026
Watch GPT-5.4 Pro vs GPT-5.5 Pro
One weekly email when material rank, price, or benchmark evidence changes make this matchup worth revisiting.
Read a sample issueJoin 2,000+ readers.