Long documents
Prompts that approach the documented context limit
GPT-4.1 nano
GPT-4.1 nano has the larger documented context window.
Confidence: documented
GPT-4.1 nano vs Kimi K2.5 (Reasoning)
Updated September 29, 2026. We do not rank this pair: at least one has no public score. Public scores include evidence status and uncertainty.
Both of these models will change. Get the price, version and retirement notices for the pair, each with its source. Follow model changes
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Decision reading
At least one model is not scored in the current public ranking lane, so the page does not name an overall quality winner. 1 results are shared. Category rows resting on Estimated evidence or different benchmark sets are marked directional and do not name a winner.
- Shared results
- 1
- GPT-4.1 nano only
- 3
- Kimi K2.5 (Reasoning) only
- 8
- Like-for-like categories
- 0 / 8
Estimated: GPT-4.1 nanoHow the comparison works
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.
Chat turn cost
1K fresh input + 500 output tokens
GPT-4.1 nano
GPT-4.1 nano has the lower estimated token cost for this stated workload. Costs use the listed standard API rates.
Confidence: listed-ratesCache-heavy agent loop cost
200K cached + 20K fresh input + 10K output tokens
GPT-4.1 nano
GPT-4.1 nano has the lower estimated token cost for this stated workload. GPT-4.1 nano has no published cached-input rate, so cached tokens use its listed input rate. Kimi K2.5 (Reasoning) 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
GPT-4.1 nano
GPT-4.1 nano has the lower estimated token cost for this stated workload. Costs use the listed standard API rates.
Confidence: listed-ratesCoding work
Code generation, repair, and software-engineering tasks
Not enough matched evidence
Kimi K2.5 (Reasoning) is not ranked on the public lane for coding, so no winner is named for coding.
Confidence: limitedAgentic work
Tool use, computer use, and multi-step task completion
Not enough matched evidence
GPT-4.1 nano and Kimi K2.5 (Reasoning) are not ranked on the public lane for agentic, so no winner is named for agentic.
Confidence: limited
Which one for a specific job
Choose a job from the LLM Selector's task catalog to see the category row it rests on, under the same basis rules as the table below. A directional row stays directional; choosing a job never creates a winner.
The same task catalog as the LLM Selector. Each job names the evidence surface it rests on; nothing here adds a new score.
14.8GPT-4.1 nano—Kimi K2.5 (Reasoning)
Not comparable · BenchAlign v5.7
The coding row is not comparable on the public lane: at least one model is not measured or not ranked there.
Coding scores combine specific tasks and setups. Match the editor, harness, and effort to your workflow.
Same basis rules as the category table below
What is actually comparable
Shared results can support a head-to-head reading. Results present for only one model describe coverage, not superiority.
3 GPT-4.1 nano only
1 Shared
8 Kimi K2.5 (Reasoning) only
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.
GPQAKnowledge
Normalized gap 37.3GPT-4.1 nano:50.3%Kimi K2.5 (Reasoning):87.6%
Bars run 0–100 on each benchmark’s normalized display scale
Category results, on a stated basis
Each row shows the public-lane category score for both models: the BenchAlign v5.7 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.
Agentic
Not comparable- GPT-4.1 nano
- Not ranked
- Kimi K2.5 (Reasoning)
- Not ranked
- Basis
- BenchAlign v5.7 lane · 0 vs 3 public rows
- Reading
- Not comparable
Coding
Not comparable- GPT-4.1 nano
- 14.8
- Estimated · #137/143
- Kimi K2.5 (Reasoning)
- Not ranked
- Basis
- BenchAlign v5.7 lane · 0 vs 2 public rows
- Reading
- Not comparable
Reasoning
Not comparable- GPT-4.1 nano
- 36.1
- Unranked · 2 rankable rows
- Kimi K2.5 (Reasoning)
- Not ranked
- Basis
- Provisional lane · 0 vs 0 weighted rows
- Reading
- Not comparable
Multimodal
Not comparable- GPT-4.1 nano
- 26.4
- Unranked · 1 rankable row
- Kimi K2.5 (Reasoning)
- 64.4
- Unranked · 1 rankable row
- Basis
- Provisional lane · 0 vs 1 weighted rows
- Reading
- Not comparable
Knowledge
Not comparable- GPT-4.1 nano
- 25.2
- Supported · #162/169
- Kimi K2.5 (Reasoning)
- Not ranked
- Basis
- BenchAlign v5.7 lane · 2 vs 2 public rows
- Reading
- Not comparable
Multilingual
Not comparable- GPT-4.1 nano
- Not ranked
- Kimi K2.5 (Reasoning)
- Not ranked
- Basis
- Provisional lane · 0 vs 0 weighted rows
- Reading
- Not comparable
Instruction following
Not comparable- GPT-4.1 nano
- 34.6
- #109/124
- Kimi K2.5 (Reasoning)
- Not ranked
- Basis
- Provisional lane · 0 vs 0 weighted rows
- Reading
- Not comparable
Math
Not comparable- GPT-4.1 nano
- 25.4
- Unranked · 1 rankable row
- Kimi K2.5 (Reasoning)
- Not ranked
- Basis
- Provisional lane · 1 vs 0 weighted rows
- Reading
- Not comparable
| Category | GPT-4.1 nano | Kimi K2.5 (Reasoning) | Basis | Reading |
|---|---|---|---|---|
| Agentic | Not ranked | Not ranked | Not comparableBenchAlign v5.7 lane · 0 vs 3 public rows | Not comparable |
| Coding | 14.8Estimated · #137/143 | Not ranked | Not comparableBenchAlign v5.7 lane · 0 vs 2 public rows | Not comparable |
| Reasoning | 36.1Unranked · 2 rankable rows | Not ranked | Not comparableProvisional lane · 0 vs 0 weighted rows | Not comparable |
| Multimodal | 26.4Unranked · 1 rankable row | 64.4Unranked · 1 rankable row | Not comparableProvisional lane · 0 vs 1 weighted rows | Not comparable |
| Knowledge | 25.2Supported · #162/169 | Not ranked | Not comparableBenchAlign v5.7 lane · 2 vs 2 public rows | Not comparable |
| Multilingual | Not ranked | Not ranked | Not comparableProvisional lane · 0 vs 0 weighted rows | Not comparable |
| Instruction following | 34.6#109/124 | Not ranked | Not comparableProvisional lane · 0 vs 0 weighted rows | Not comparable |
| Math | 25.4Unranked · 1 rankable row | Not ranked | Not comparableProvisional lane · 1 vs 0 weighted rows | Not comparable |
Ranks count the models scored in each category’s lane, so the agentic, coding, and knowledge denominators (BenchAlign v5.7) differ from the provisional-lane categories. Unranked scores sit on the provisional lane’s scale but never name a winner. Like-for-like rows within 0.5 points read as a practical tie.
Supported evidence per lane · bars run 0–100Methodology
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-4.1 nano
- $0.0003
- Fits in one request
- Kimi K2.5 (Reasoning)
- $0.0021
- Fits in one request
GPT-4.1 nano has the lower modeled cost
Costs use the listed standard API rates.
Repository review
50K fresh input + 3K output tokens
- GPT-4.1 nano
- $0.0062
- Fits in one request
- Kimi K2.5 (Reasoning)
- $0.039
- Fits in one request
GPT-4.1 nano 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-4.1 nano
- $0.026
- Fits in one request
- Cached input priced at the published list-input rate
- Kimi K2.5 (Reasoning)
- $0.162
- Fits in one request
- Cached input priced at the published list-input rate
GPT-4.1 nano has the lower modeled cost
GPT-4.1 nano has no published cached-input rate, so cached tokens use its listed input rate. Kimi K2.5 (Reasoning) has no published cached-input rate, so cached tokens use its listed input rate.
Cached input falls back to the list input rate only where a cached rate is unpublished
Specification differences
Sourced differences are shown directly. Missing facts stay explicit instead of being inferred from a model name or family.
SpecificationGPT-4.1 nanoKimi K2.5 (Reasoning)
Context window
Maximum documented context; output-token limits may be lower.
GPT-4.1 nano
1M
Kimi K2.5 (Reasoning)
256K
API model ID
GPT-4.1 nano
Not sourced
Kimi K2.5 (Reasoning)
Not sourced
Cached-input rate
A missing cached-input rate falls back to the listed input rate only in the stated workload estimate.
GPT-4.1 nano
Not published
Kimi K2.5 (Reasoning)
Not published
Documented inputs
GPT-4.1 nano
Not sourced
Kimi K2.5 (Reasoning)
Not sourced
Documented outputs
GPT-4.1 nano
Not sourced
Kimi K2.5 (Reasoning)
Not sourced
Provider availability
GPT-4.1 nano
Not sourced
Kimi K2.5 (Reasoning)
Not sourced
Reasoning profile
GPT-4.1 nano
Non-Reasoning
Kimi K2.5 (Reasoning)
Reasoning
Weight access
GPT-4.1 nano
Proprietary
Kimi K2.5 (Reasoning)
Proprietary
License
GPT-4.1 nano
Proprietary
Kimi K2.5 (Reasoning)
Proprietary
Release date
GPT-4.1 nano
2025-04-14
Kimi K2.5 (Reasoning)
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
- At least one model is not scored in the current public ranking lane, so the page does not name an overall quality winner.
- Workload cost
- Repository review: $0.0062 vs $0.039. Cache-heavy agent loop: $0.026 vs $0.162.
- Context tradeoff
- GPT-4.1 nano has the larger documented window (1M).
Run the same representative tasks against both endpoints before changing production traffic.
Questions
Which is better, GPT-4.1 nano or Kimi K2.5 (Reasoning)?
At least one model is not scored in the current public ranking lane, so the page does not name an overall quality winner. The page therefore keeps the decision tied to the specific documented workload.
Which is better for coding, GPT-4.1 nano or Kimi K2.5 (Reasoning)?
Kimi K2.5 (Reasoning) is not ranked on the public lane for coding, so no winner is named for coding.
Which is better for agentic tasks, GPT-4.1 nano or Kimi K2.5 (Reasoning)?
GPT-4.1 nano and Kimi K2.5 (Reasoning) are not ranked on the public lane for agentic tasks, so no winner is named for agentic tasks.
Which costs less, GPT-4.1 nano or Kimi K2.5 (Reasoning)?
For the stated presets, chat costs $0.0003 on GPT-4.1 nano and $0.0021 on Kimi K2.5 (Reasoning); repository review costs $0.0062 and $0.039; the cache-heavy agent loop costs $0.026 and $0.162. GPT-4.1 nano has no published cached-input rate, so cached tokens use its listed input rate. Kimi K2.5 (Reasoning) has no published cached-input rate, so cached tokens use its listed input rate.
Which has the larger context window, GPT-4.1 nano or Kimi K2.5 (Reasoning)?
GPT-4.1 nano has the larger documented context window: 1M, compared with 256K.
Benchmark evidence
The full public result ledger is available for audit without forcing a wide desktop table onto a phone.
Browse raw public benchmark evidence12 rows
12 public results · 1 shared
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Last updated September 29, 2026