Agentic
Directional only- GPT-5.5 Pro
- 60.6
- Estimated · #24/151
- Kimi K2.5
- 46.0
- Estimated · #90/151
- Basis
- BenchAlign lane · 1 vs 14 public rows
- Reading
- Directional only
GPT-5.5 Pro vs Kimi K2.5
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 55.62, but the 90% score intervals overlap. Treat that as a lead, not a settled winner.
4 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.
Long documents
Prompts that approach the documented context limit
GPT-5.5 Pro
GPT-5.5 Pro has the larger documented context window.
Confidence: documented
Chat turn cost
1K fresh input + 500 output tokens
Kimi K2.5
Kimi K2.5 has the lower estimated token cost for this stated workload. Costs use the listed standard API rates.
Confidence: listed-rates
Cache-heavy agent loop cost
200K cached + 20K fresh input + 10K output tokens
Kimi K2.5
Kimi K2.5 has the lower estimated token cost for this stated workload. GPT-5.5 Pro has no published cached-input rate, so cached tokens use its listed input rate. Kimi K2.5 has no published cached-input rate, so cached tokens use its listed input rate.
Confidence: rate-fallback
Show secondary and unsupported calls
Repository review cost
50K fresh input + 3K output tokens
Kimi K2.5
Kimi K2.5 has the lower estimated token cost for this stated workload. Costs use the listed standard API rates.
Confidence: listed-rates
Coding work
Code generation, repair, and software-engineering tasks
Not enough matched evidence
GPT-5.5 Pro is 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-5.5 Pro and Kimi K2.5 are scored on Estimated evidence for agentic, so the reading is directional rather than like-for-like.
Confidence: limited
What is actually comparable
Shared results can support a head-to-head reading. Results present for only one model describe coverage, not superiority.
2 GPT-5.5 Pro only
4 Shared
41 Kimi K2.5 only
- Shared results
- 4
- GPT-5.5 Pro only
- 2
- Kimi K2.5 only
- 41
- 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-5.5 Pro
- 61.1
- Estimated · #36/181
- Kimi K2.5
- 53.1
- Estimated · #70/181
- Basis
- BenchAlign lane · 2 vs 6 public rows
- Reading
- Directional only
Coding
Not comparable- GPT-5.5 Pro
- Not ranked
- Kimi K2.5
- 51.5
- Estimated · #64/183
- Basis
- BenchAlign lane · 0 vs 8 public rows
- Reading
- Not comparable
Reasoning
Not comparable- GPT-5.5 Pro
- Not ranked
- Kimi K2.5
- 53.5
- Unranked · 3 rankable rows
- Basis
- Provisional lane · 0 vs 1 weighted rows
- Reading
- Not comparable
Math
Not comparable- GPT-5.5 Pro
- 70.2
- Unranked · 3 rankable rows
- Kimi K2.5
- 62.4
- #5/7
- Basis
- Provisional lane · 2 vs 4 weighted rows
- Reading
- Not comparable
Multilingual
Not comparable- GPT-5.5 Pro
- Not ranked
- Kimi K2.5
- 38.2
- #8/12
- Basis
- Provisional lane · 0 vs 1 weighted rows
- Reading
- Not comparable
Multimodal
Not comparable- GPT-5.5 Pro
- Not ranked
- Kimi K2.5
- 65.7
- #24/48
- Basis
- Provisional lane · 0 vs 1 weighted rows
- Reading
- Not comparable
Instruction following
Not comparable- GPT-5.5 Pro
- Not ranked
- Kimi K2.5
- 85.6
- #40/120
- Basis
- Provisional lane · 0 vs 0 weighted rows
- Reading
- Not comparable
| Category | GPT-5.5 Pro | Kimi K2.5 | Basis | Reading |
|---|---|---|---|---|
| Agentic | 60.6Estimated · #24/151 | 46.0Estimated · #90/151 | Directional onlyBenchAlign lane · 1 vs 14 public rows | Directional only |
| Knowledge | 61.1Estimated · #36/181 | 53.1Estimated · #70/181 | Directional onlyBenchAlign lane · 2 vs 6 public rows | Directional only |
| Coding | Not ranked | 51.5Estimated · #64/183 | Not comparableBenchAlign lane · 0 vs 8 public rows | Not comparable |
| Reasoning | Not ranked | 53.5Unranked · 3 rankable rows | Not comparableProvisional lane · 0 vs 1 weighted rows | Not comparable |
| Math | 70.2Unranked · 3 rankable rows | 62.4#5/7 | Not comparableProvisional lane · 2 vs 4 weighted rows | Not comparable |
| Multilingual | Not ranked | 38.2#8/12 | Not comparableProvisional lane · 0 vs 1 weighted rows | Not comparable |
| Multimodal | Not ranked | 65.7#24/48 | Not comparableProvisional lane · 0 vs 1 weighted rows | Not comparable |
| Instruction following | Not ranked | 85.6#40/120 | 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
BrowseComp
Agentic
HLE
Knowledge
FrontierMath v2 (Tiers 1-3)
Math
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-5.5 Pro
- $0.12
- Fits in one request
- Kimi K2.5
- $0.0021
- Fits in one request
Kimi K2.5 has the lower modeled cost
Costs use the listed standard API rates.
Repository review
50K fresh input + 3K output tokens
- GPT-5.5 Pro
- $2.04
- Fits in one request
- Kimi K2.5
- $0.039
- Fits in one request
Kimi K2.5 has the lower modeled cost
Costs use the listed standard API rates.
Cache-heavy agent loop
200K cached + 20K fresh input + 10K output tokens
- GPT-5.5 Pro
- $8.40
- Fits in one request
- Cached input priced at the published list-input rate
- Kimi K2.5
- $0.162
- Fits in one request
- Cached input priced at the published list-input rate
Kimi K2.5 has the lower modeled cost
GPT-5.5 Pro has no published cached-input rate, so cached tokens use its listed input rate. Kimi K2.5 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-5.5 ProKimi K2.5
Context window
Maximum documented context; output-token limits may be lower.
GPT-5.5 Pro
Kimi K2.5
256K
API model ID
GPT-5.5 Pro
gpt-5.5-pro
OpenAI GPT-5.5 Pro model documentationKimi K2.5
Not sourced
Cached-input rate
A missing cached-input rate falls back to the listed input rate only in the stated workload estimate.
GPT-5.5 Pro
Not published
OpenAI pricingKimi K2.5
Not published
Documented inputs
GPT-5.5 Pro
text, image
OpenAI model catalogKimi K2.5
Not sourced
Documented outputs
GPT-5.5 Pro
Kimi K2.5
Not sourced
Provider availability
GPT-5.5 Pro
Generally Available · OpenAI Responses API
OpenAI model catalogKimi K2.5
Not sourced
Reasoning profile
GPT-5.5 Pro
Reasoning
Kimi K2.5
Non-Reasoning
Weight access
GPT-5.5 Pro
Proprietary
Kimi K2.5
Open Weight
License
GPT-5.5 Pro
Proprietary
Kimi K2.5
Open Weight
Release date
GPT-5.5 Pro
2026-04-23
Kimi K2.5
2026-02-01
If you already use one of these models
- Deployment change
- The models list different providers, so authentication, endpoint behavior, limits, and feature support may change.
- Quality signal
- GPT-5.5 Pro has the higher public score estimate, 63.07 versus 55.62, but the 90% score intervals overlap.
- Workload cost
- Repository review: $2.04 vs $0.039. Cache-heavy agent loop: $8.40 vs $0.162.
- Context tradeoff
- GPT-5.5 Pro has the larger documented window (1.05M).
Run the same representative tasks against both endpoints before changing production traffic.
Self-host vs API cost
Estimates at 50,000 req/day · 1000 tokens/req average.
GPT-5.5 Pro
API / mo$157,500
Self-host / moNot listed
Break-even—
Proprietary model — self-hosting not applicable.
Kimi K2.5
API / mo$2,700
Self-host / mo$5,221
Break-even132M/day
Benchmark evidence
The full public result ledger is available for audit without forcing a wide desktop table onto a phone.
Browse raw public benchmark evidence47 rows
Agentic
BrowseComp
GPT-5.5 Pro90.1%SourceKimi K2.560.6%SourceGPT-5.5 Pro leads this result
Terminal-Bench 2.0
GPT-5.5 Pro—Kimi K2.550.8%SourceNot directly comparable
Claw-Eval
GPT-5.5 Pro—Kimi K2.552.3%SourceNot directly comparable
QwenClawBench
GPT-5.5 Pro—Kimi K2.554.3%SourceNot directly comparable
τ³-bench results
GPT-5.5 Pro—Kimi K2.565.7%SourceNot directly comparable
DeepSearchQA
GPT-5.5 Pro—Kimi K2.577.1%SourceNot directly comparable
DeepPlanning
GPT-5.5 Pro—Kimi K2.514.4%SourceNot directly comparable
Toolathlon
GPT-5.5 Pro—Kimi K2.527.8%SourceNot directly comparable
MCP Atlas
GPT-5.5 Pro—Kimi K2.529.5%SourceNot directly comparable
MCP-Tasks
GPT-5.5 Pro—Kimi K2.559.1%SourceNot directly comparable
WideResearch
GPT-5.5 Pro—Kimi K2.572.7%SourceNot directly comparable
Gert Labs
GPT-5.5 Pro—Kimi K2.545.88%SourceNot directly comparable
ResearchClawBench
GPT-5.5 Pro—Kimi K2.514.0%SourceNot directly comparable
JobBench
GPT-5.5 Pro—Kimi K2.58.7%SourceNot directly comparable
Coding
SWE-bench Verified
GPT-5.5 Pro—Kimi K2.576.8%SourceNot directly comparable
SWE-bench Verified*
GPT-5.5 Pro—Kimi K2.570.8%SourceNot directly comparable
LiveCodeBench v6
GPT-5.5 Pro—Kimi K2.585.0%SourceNot directly comparable
SWE-bench Pro
GPT-5.5 Pro—Kimi K2.550.7%SourceNot directly comparable
SWE Multilingual
GPT-5.5 Pro—Kimi K2.573%SourceNot directly comparable
SWE-Rebench
GPT-5.5 Pro—Kimi K2.558.5%SourceNot directly comparable
React Native Evals
GPT-5.5 Pro—Kimi K2.577.2%SourceNot directly comparable
SciCode
GPT-5.5 Pro—Kimi K2.548.7%SourceNot directly comparable
Reasoning
LongBench v2
GPT-5.5 Pro—Kimi K2.561%SourceNot directly comparable
Knowledge
HLE
GPT-5.5 Pro57.2%SourceKimi K2.530.1%SourceGPT-5.5 Pro leads this result
HLE w/o tools
GPT-5.5 Pro43.1%SourceKimi K2.5—Not directly comparable
GPQA
GPT-5.5 Pro—Kimi K2.587.6%SourceNot directly comparable
GPQA-D
GPT-5.5 Pro—Kimi K2.587.6%SourceNot directly comparable
SuperGPQA
GPT-5.5 Pro—Kimi K2.569.2%SourceNot directly comparable
MMLU-Pro
GPT-5.5 Pro—Kimi K2.587.1%SourceNot directly comparable
MMLU-Pro (Arcee)
GPT-5.5 Pro—Kimi K2.587.1%SourceNot directly comparable
Math
FrontierMath (legacy)
GPT-5.5 Pro52.4%SourceKimi K2.5—Not directly comparable
FrontierMath v2 (Tiers 1-3)
Shared sourceGPT-5.5 Pro51.000%Kimi K2.527.900%GPT-5.5 Pro leads this result
FrontierMath v2 (Tier 4)
Shared sourceGPT-5.5 Pro39.600%Kimi K2.54.200%GPT-5.5 Pro leads this result
AIME 2025
GPT-5.5 Pro—Kimi K2.596.1%SourceNot directly comparable
AIME26
GPT-5.5 Pro—Kimi K2.595.8%SourceNot directly comparable
AIME25 (Arcee)
GPT-5.5 Pro—Kimi K2.596.3%SourceNot directly comparable
HMMT Feb 2025
GPT-5.5 Pro—Kimi K2.595.4%SourceNot directly comparable
HMMT Nov 2025
GPT-5.5 Pro—Kimi K2.591.1%SourceNot directly comparable
HMMT Feb 2026
GPT-5.5 Pro—Kimi K2.587.1%SourceNot directly comparable
MMAnswerBench
GPT-5.5 Pro—Kimi K2.581.8%SourceNot directly comparable
Multilingual
Multimodal
Instruction following
IFEval
GPT-5.5 Pro—Kimi K2.593.9%SourceNot directly comparable
Frequently asked questions
Which is better, GPT-5.5 Pro or Kimi K2.5?
GPT-5.5 Pro has the higher public score estimate, 63.07 versus 55.62, 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-5.5 Pro or Kimi K2.5?
GPT-5.5 Pro is not ranked on the public lane for coding, so no winner is named for coding.
Which is better for agentic tasks, GPT-5.5 Pro or Kimi K2.5?
GPT-5.5 Pro scores higher for agentic tasks on the public lane, 60.6 to 46. GPT-5.5 Pro and Kimi K2.5 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-5.5 Pro or Kimi K2.5?
For the stated presets, chat costs $0.12 on GPT-5.5 Pro and $0.0021 on Kimi K2.5; repository review costs $2.04 and $0.039; the cache-heavy agent loop costs $8.40 and $0.162. GPT-5.5 Pro has no published cached-input rate, so cached tokens use its listed input rate. Kimi K2.5 has no published cached-input rate, so cached tokens use its listed input rate.
Which has the larger context window, GPT-5.5 Pro or Kimi K2.5?
GPT-5.5 Pro has the larger documented context window: 1.05M, compared with 256K.
Related comparisons
Last updated September 4, 2026
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