Is GPT-5.6 Sol better than Kimi K2.5?

GPT-5.6 Sol (max) leads on quality: 65.4 vs 58.8. The BenchLeader Index combines every independent quality benchmark; GPT-5.6 Sol (max) is ahead overall as of 29 Oct 2026, but check the category scores for your use.

GPT-5.6 Sol vs Kimi K2.5: which is cheaper, and will that change?

Kimi K2.5 is cheaper today: $1.20 against $8.00 per million tokens, blended at three input tokens per output token. No price change has been announced for either.

Is GPT-5.6 Sol or Kimi K2.5 better for coding?

GPT-5.6 Sol scores higher in coding (66 vs 56 on the category index, where 50 is average). On LiveCodeBench, the top shared coding benchmark, it is 82.6% for GPT-5.6 Sol against 83.9% for Kimi K2.5.

Which is faster, GPT-5.6 Sol or Kimi K2.5?

Kimi K2.5 streams faster (87 vs 85 output tokens per second, Artificial Analysis 7-day median).

Is GPT-5.6 Sol or Kimi K2.5 better for agents and tool use?

GPT-5.6 Sol scores higher in agentic tasks (67 vs 45 on the category index, where 50 is average). On τ³-Banking (AA), the top shared agents & tools benchmark, it is 44.3% for GPT-5.6 Sol against 14.2% for Kimi K2.5.

Which is better for long documents?

GPT-5.6 Sol scores higher on long-context benchmarks (67 vs 64). GPT-5.6 Sol accepts more context: 1,050,000 against 262,144 tokens for Kimi K2.5.

Which has lower latency?

Kimi K2.5 answers first: 36.0 s against 86.2 s to the first answer token, as Artificial Analysis measures it. Reasoning effort drives most of this: a higher setting thinks longer before it answers.

When was GPT-5.6 Sol released?

GPT-5.6 Sol was released on 9 Jul 2026.

GPT-5.6 Sol vs Kimi K2.5

Full profiles: GPT-5.6 Sol (OpenAI) and Kimi K2.5 (Moonshot AI): every benchmark, price and rank.

Updated 28 Oct 2026 · Data from 13 sources

As of 29 Oct 2026, GPT-5.6 Sol is ahead of Kimi K2.5 on quality (65.4 vs 58.8 on the BenchLeader Index), but Kimi K2.5 is 6.7× cheaper at $1.20 vs $8.00 per 1M tokens blended. Choose GPT-5.6 Sol for agents & tools (67 vs 45), maths (71 vs 56), and coding (66 vs 56); choose Kimi K2.5 for fast first answers (36.0 s vs 86.2 s) and reasoning (67 vs 65).

Key facts (as of 29 Oct 2026)

GPT-5.6 Sol scores 65.4 on the BenchLeader Index and Kimi K2.5 scores 58.8 (BenchLeader, 29 Oct 2026).
GPT-5.6 Sol costs $8.00 per 1M tokens blended (list price, 29 Oct 2026).
Kimi K2.5 costs $1.20 per 1M tokens blended (list price, 29 Oct 2026).
Of the 28 benchmarks both models have, GPT-5.6 Sol leads 25 (BenchLeader, 29 Oct 2026).

GPT-5.6 Sol benchmarks max OpenAI

Kimi K2.5 benchmarks thinking Moonshot AI Open in the comparison tool

Which to pick for…

The pick's numbers come first. Category scores on the BenchLeader scale (50 is the average model, 15 points one standard deviation). High confidence means a lead of half a standard deviation or more; under one point is called either.

Use case	Pick	Why	Confidence
Coding	GPT-5.6 Sol	66 vs 56 category score; LiveCodeBench 82.6% vs 83.9%	High
Agents & tool use	GPT-5.6 Sol	67 vs 45 category score; τ³-Banking (AA) 44.3% vs 14.2%	High
Maths	GPT-5.6 Sol	71 vs 56 category score	High
Reasoning	Kimi K2.5	67 vs 65 category score; GPQA Diamond (AA) 87.9% vs 94.1%	Medium
Knowledge	GPT-5.6 Sol	64 vs 60 category score; MMLU-Pro 89.1% vs 85.9%	Medium
Long documents	GPT-5.6 Sol	67 vs 64 category score; AA-LCR v1.1 84.0% vs 78.0%	Medium
Images and other media	GPT-5.6 Sol	66 vs 59 category score; MMMU-Pro 83.4% vs 75.4%	Medium
Following instructions	GPT-5.6 Sol	71 vs 69 category score; IFBench 72.7% vs 70.2%	Medium
Chat quality (human preference)	–	Only Kimi K2.5 has an Arena rating (63 category score)	Not comparable
Lowest cost	Kimi K2.5	$1.20 vs $8.00 per 1M blended; agentic coding session $0.048 vs $0.320	–
Fastest first answer	Kimi K2.5	36.0 s (Kimi K2.5 (thinking)) vs 86.2 s (GPT-5.6 Sol (max)) to the first answer token	–
High volume on a budget	Neither flagship	A smaller model is usually the better fit: Cheapest good LLMs, Fastest LLMs	–

Key differences

GPT-5.6 Sol (max) leads on quality: 65.4 vs 58.8.
GPT-5.6 Sol (max) is stronger in agents & tools, coding, instruction following, knowledge, long context, maths, multimodal.
Kimi K2.5 (thinking) is stronger in reasoning, human preference.
Kimi K2.5 (thinking) is 6.7× cheaper ($1.20 vs $8.00 per 1M blended).

At a glance

Spec	GPT-5.6 Sol	Kimi K2.5
Developer	OpenAI	Moonshot AI
Released	9 Jul 2026	27 Jan 2026
Context window (tokens)	1,050,000	262,144
Compared at	GPT-5.6 Sol (max)	Kimi K2.5 (thinking)
Open weights	No	Yes
Price in / out / cached input per 1M	$4.00 / $20.00 / $0.400	$0.600 / $3.00 / $0.100

Category by category

Category scores on the BenchLeader scale: 50 is the average evaluated model, 15 points is one standard deviation. A gap under one point is called level.

Category	GPT-5.6 Sol (max)	Kimi K2.5 (thinking)	Leader
Reasoning	65.1	67.3	Kimi K2.5
Coding	65.8	55.7	GPT-5.6 Sol
Agents & tools	66.6	45.1	GPT-5.6 Sol
Maths	70.8	56.2	GPT-5.6 Sol
Knowledge	63.9	60.0	GPT-5.6 Sol
Instruction following	71.1	69.0	GPT-5.6 Sol
Human preference	–	63.4	not comparable
Multimodal	66.2	59.3	GPT-5.6 Sol
Long context	66.9	63.8	GPT-5.6 Sol

Where sources disagree

Across the 28 benchmarks both have, GPT-5.6 Sol leads 25, Kimi K2.5 leads 3. Every overall index that rates both puts GPT-5.6 Sol ahead.

Overall index	GPT-5.6 Sol (max)	Kimi K2.5 (thinking)	Leader
BenchLeader Index	65.4	58.8	GPT-5.6 Sol
Arena Text	1485†	1450	GPT-5.6 Sol

Each publisher runs its own tasks, harnesses and effort settings, so their overall verdicts can differ; BenchLeader reconciles them on one scale. † measured at another effort setting of the same model (the publisher did not test the one compared here).

Price, speed and latency

List prices blended at three input tokens per output token. Per-task prices use the token counts on the methodology page; suite cost is what Artificial Analysis paid to run its whole Intelligence Index.

Measure	GPT-5.6 Sol (max)	Kimi K2.5 (thinking)
Blended price per 1M tokens	$8.00	$1.20
Input / output per 1M	$4.00 / $20.00	$0.600 / $3.00
Cached input per 1M	$0.400	$0.100
Price per task: chat reply	$0.0076	$0.0011
Price per task: summarize a 30-page report	$0.060	$0.0090
Price per task: code edit	$0.054	$0.0081
Price per task: agentic coding session	$0.320	$0.048
Price per task: structured extraction	$0.012	$0.0018
Output speed	85 tok/s	87 tok/s
Time to first answer	86.2 s	36.0 s
Time to a complete answer	92.1 s	41.7 s

Each model is compared at its best-ranked reasoning-effort setting. GPT-5.6 Sol (max) scores 65.4 and takes 86 s to its first answer token; GPT-5.6 Sol (xhigh) scores 64.4 in 22 s, GPT-5.6 Sol (high) scores 63.6 in 11 s. Kimi K2.5 (thinking) scores 58.8 and takes 36 s to its first answer token; Kimi K2.5 scores 54.3 in 1 s. Higher effort means more thinking before the answer: better scores, longer waits and more tokens billed. How reasoning effort changes scores and cost.

Every benchmark

151 benchmarks, grouped by category; each name links to the board and its leaders. † measured at another effort setting of the same model, shown for reference and not counted as a win.

Metric	Publisher	GPT-5.6 Sol (max)	Kimi K2.5 (thinking)
BenchLeader Index	BenchLeader	65.4	58.8
Agents & tools score	BenchLeader	66.6	45.1
Coding score	BenchLeader	65.8	55.7
Instruction following score	BenchLeader	71.1	69.0
Knowledge score	BenchLeader	63.9	60.0
Long context score	BenchLeader	66.9	63.8
Maths score	BenchLeader	70.8	56.2
Multimodal score	BenchLeader	66.2	59.3
Reasoning score	BenchLeader	65.1	67.3
Human preference score	BenchLeader	–	63.4
Blended price $/M	BenchLeader	$8.00	$1.20
Output speed	BenchLeader	85 tok/s	87 tok/s
Time to first answer	BenchLeader	86.2 s	36.0 s
Context window	BenchLeader	1,050,000 tokens	262,144 tokens
Reasoning
GPQA Diamond	Epoch AI Benchmarking Hub	93.5%	87.6%†
Humanity's Last Exam	Scale AI / CAIS	–	24.4%†
SimpleBench	SimpleBench	64.8%†	46.8%†
Arena Hard Prompts	Arena (LMArena)	1512†	1471
LiveBench 1.0 Reasoning	LiveBench	91.7%	–
GPQA Diamond (AA)	Artificial Analysis	94.1%	87.9%
Humanity's Last Exam (AA)	Artificial Analysis	49.5%	30.7%
GPQA Diamond (Vals)	Vals AI	95.2%	84.1%
EnigmaEval	Scale AI SEAL	37.1%†	–
Kagi LLM Benchmark	Kagi LLM Benchmark	67.0%†	78.5%
ARC-AGI-1	ARC Prize	96.5%	65.3%†
ARC-AGI-2	ARC Prize	92.5%	11.8%†
ARC-AGI-3	ARC Prize	7.8%	–
CritPt	Artificial Analysis	32.3%	3.1%
CritPt v2 hard subset (AA)	Artificial Analysis	56.0%	–
MysteryMechanism	Vals AI	33.3%	–
Chess Puzzles	Epoch AI Benchmarking Hub	59.0%	–
Mystery Game Puzzles	Epoch AI Benchmarking Hub	58.0%	–
CL-bench	Epoch AI Benchmarking Hub	–	19.3%†
CL-bench Life	Epoch AI Benchmarking Hub	–	13.2%†
LMCA	Epoch AI Benchmarking Hub	58.4%	–
DTBench	Epoch AI Benchmarking Hub	95.5%	–
ForecastBench	ForecastBench	65.5%	–
BTF-3	Epoch AI Benchmarking Hub	13.7%	–
Coding
SWE-bench Verified (Epoch)	Epoch AI Benchmarking Hub	–	73.8%†

Show all 151 benchmarks

Metric	Publisher	GPT-5.6 Sol (max)	Kimi K2.5 (thinking)
Coding
SciCode	SciCode	57.1%	49.0%†
WeirdML	WeirdML	87.0%	45.6%†
FrontierCode	Cognition	47.5%†	–
GSO-Bench	GSO-Bench	76.5%†	–
Arena Coding	Arena (LMArena)	1534†	1502
Arena WebDev	Arena (LMArena)	1616†	1437
LiveBench 1.0 Coding	LiveBench	83.9%	–
SciCode (AA)	Artificial Analysis	57.1%	–
LiveCodeBench	Vals AI	82.6%	83.9%
IOI	Vals AI	91.2%	–
SWE-bench (Vals)	Vals AI	96.2%	70.0%
SWE-bench Verified (bash only)	SWE-bench	–	70.8%†
SWE-bench Verified (any scaffold)	SWE-bench	–	70.8%†
Code Migration	Vals AI	52.9%	7.0%
ProgramBench	Vals AI	1.5%	–
Vibe Code Bench 1-100	Vals AI	20.0%	–
Vibe Code Bench v1.1	Vals AI	80.5%	17.5%
SWE Atlas: Codebase QnA	Scale AI SEAL	46.0%†	13.1%†
SWE Atlas: Refactoring	Scale AI SEAL	–	20.9%†
SWE Atlas: Test Writing	Scale AI SEAL	45.9%†	25.8%†
MirrorCode	Epoch AI Benchmarking Hub	20.0%†	–
Surface Evolver Bench	Epoch AI Benchmarking Hub	93.1%†	–
DeepSWE v1.1	Epoch AI Benchmarking Hub	72.7%	–
CursorBench	Cursor	41.7%	–
ALE-Bench	Epoch AI Benchmarking Hub	2176.9	821.6†
FrontierSWE	Epoch AI Benchmarking Hub	32.2%	–
Terminal-Bench 4.0 (AA)	Artificial Analysis	39.9%	–
Terminal-Bench 2.1 (AA)	Artificial Analysis	88.0%	45.7%
Startrise Frontend	Startrise	66.2%†	–
Agents & tools
Terminal-Bench	Terminal-Bench	37.3%	43.2%†
OSWorld-Verified 2.0	OSWorld	27.3%	–
Arena Agent	Arena (LMArena)	6.1†	–
LiveBench Agentic Coding	LiveBench	56.2%	–
Terminal-Bench Hard	Artificial Analysis	65.9%	34.9%
τ²-Bench Telecom (AA)	Artificial Analysis	85.1%	95.9%
Terminal-Bench 2.1 (Vals)	Vals AI	85.8%	42.0%
MCP Atlas	Scale AI SEAL	–	64.4%†
HiL-Bench	Scale AI SEAL	32.3%†	–
τ³-bench Banking	τ²-bench	46.9%†	–
τ³-Banking (AA)	Artificial Analysis	44.3%	14.2%
ITBench SRE (AA)	Artificial Analysis	56.2%	–
Analyst Agent (AA)	Artificial Analysis	47.5%	–
APEX-Agents (AA)	Artificial Analysis	–	11.5%
CUA-bench	Vals AI	8.3%	–
CyberBench	Vals AI	76.3%	–
Finance Agent v2	Vals AI	53.8%	35.8%
Harvey's Legal Agent Benchmark v1	Vals AI	2.5%	0.0%
Legal Research Bench	Vals AI	48.1%	15.9%
SkillsBench	Vals AI	54.1%	–
SREBench	Vals AI	30.5%	–
Tax Agent Bench	Vals AI	31.1%	–
Terminal-Bench 2.0 (Vals)	Vals AI	–	40.5%
Terminal-Bench 4.0 (Vals)	Vals AI	37.9%	–
Terminal-Bench Science	Vals AI	20.0%	–
Time Horizon Index: KSP	Vals AI	23.8%	–
Web Search Index	Vals AI	43.6%	–
Arena Search	Arena (LMArena)	1258†	–
BALROG	BALROG	60.0%	–
PostTrainBench	Epoch AI Benchmarking Hub	36.2%	–
GBAEval	Epoch AI Benchmarking Hub	52.6%†	–
Vending-Bench 2	Andon Labs	9619.4†	1198.5†
AutomationBench	Artificial Analysis	60.1%	–
GDP.pdf (AA)	Artificial Analysis	27.2%	–
EnterpriseOps-Gym	Artificial Analysis	42.9%	–
AA-Briefcase v1.1	Artificial Analysis	1478	–
Terminal-Bench-Science 0.1 (AA)	Artificial Analysis	22.4%	–
FACTS Search	Google	88.5%†	–
Maths
FrontierMath Tiers 1–3	Epoch AI Benchmarking Hub	89.1%	–
FrontierMath Tier 4	Epoch AI Benchmarking Hub	82.9%	–
OTIS Mock AIME	Epoch AI Benchmarking Hub	100.0%	92.2%†
ProofBench	Vals AI	83.0%	–
LiveBench Mathematics	LiveBench	96.2%	–
AIME (Vals)	Vals AI	–	95.6%
AIME 2026	MathArena	–	95.8%
HMMT February 2026	MathArena	–	87.1%
MathArena Apex	MathArena	–	8.8%
Arena Maths	Arena (LMArena)	1496†	1471
Knowledge
SimpleQA Verified	Epoch AI Benchmarking Hub	69.7%	34.3%†
LiveBench 1.0 Data Analysis	LiveBench	79.8%	–
MMLU-Pro	Vals AI	89.1%	85.9%
LegalBench	Vals AI	87.0%	–
CorpFin	Vals AI	64.4%	68.3%
TaxEval	Vals AI	74.8%	74.2%
MedQA	Vals AI	–	94.4%
PRBench Finance	Scale AI SEAL	50.5%	46.5%†
PRBench Legal	Scale AI SEAL	50.5%	43.8%†
MultiNRC	Scale AI SEAL	–	35.2%†
BioMysteryBench	Vals AI	71.1%	–
CaseLaw v2	Vals AI	–	58.7%
Excel Modeling Benchmark	Vals AI	72.3%	28.5%
MedCode	Vals AI	44.0%	39.3%
MedScribe	Vals AI	85.2%	76.4%
Public Benefits Bench v1.1	Vals AI	66.5%	–
DrugDiscoveryBench	Scale AI SEAL	56.5%	–
EBR-bench	Epoch AI Benchmarking Hub	44.8%	–
GDP.pdf	Epoch AI Benchmarking Hub	30.7%	–
Instruction following
LiveBench Language	LiveBench	87.7%	–
LiveBench Instruction Following	LiveBench	71.8%	–
IFBench	Artificial Analysis	72.7%	70.2%
MultiChallenge	Scale AI SEAL	–	61.4%†
TutorBench	Scale AI SEAL	–	54.6%†
Arena Instruction Following	Arena (LMArena)	1491†	1439
Human preference
Arena Text	Arena (LMArena)	1485†	1450
EQ-Bench 4	EQ-Bench	1236†	–
Arena Creative Writing	Arena (LMArena)	1470†	1423
Arena Multi-turn	Arena (LMArena)	1490†	1452
Arena Longer Queries	Arena (LMArena)	1499†	1458
Multimodal
Arena Vision	Arena (LMArena)	1281†	1269
MMMU-Pro	Artificial Analysis	83.4%	75.4%
VISTA	Scale AI SEAL	–	41.9%†
MMMU-Pro (Vals)	Vals AI	88.8%	84.3%
MortgageTax	Vals AI	67.3%	66.5%
Blueprint-Bench 2	Epoch AI Benchmarking Hub	33.6%†	–
Long context
Fiction.LiveBench 120k	Fiction.live	–	78.1%†
AA-LCR v1.1	Artificial Analysis	84.0%	78.0%
Arena Document	Arena (LMArena)	1489†	1436
MLCR	Artificial Analysis	30.0%	–
Composite
Epoch Capabilities Index	Epoch AI Benchmarking Hub	162.8†	148.1†
LiveBench 1.0	LiveBench	81.0%	–
AA Intelligence Index v4.3.2	Artificial Analysis	47.0	23.5
AA Progress Index v1	Artificial Analysis	331.5	270.5
Vals RSI Index	Vals AI	23.9%	6.8%†
Vals Science Index	Vals AI	41.5%	–
Vals Multimodal Index	Vals AI	72.6%	–
Safety & honesty
FORTRESS	Scale AI SEAL	20.1%†	41.1%†
MASK	Scale AI SEAL	–	70.5%†

Data as of 2026-10-29. Best configuration of each model; every score links to its source on the model pages.

What changed

28 Oct 2026 GPT-5.6 Sol (max): 2 new results (AA Progress Index v1, CritPt v2 hard subset (AA)).
28 Oct 2026 Kimi K2.5 (thinking): 1 new result (AA Progress Index v1).
25 Oct 2026 GPT-5.6 Sol (max): 1 new result (AA-Briefcase v1.1).
23 Oct 2026 GPT-5.6 Sol (max): 3 new results (Harvey's Legal Agent Benchmark v1, Vals RSI Index, Vals Science Index).
23 Oct 2026 Kimi K2.5 (thinking): 1 new result (Harvey's Legal Agent Benchmark v1).
21 Oct 2026 GPT-5.6 Sol (max): 1 score revision.
21 Oct 2026 Kimi K2.5 (thinking): output price moved from $2.75/M to $3.00/M (9% up).
20 Oct 2026 GPT-5.6 Sol (max): 1 new result (ForecastBench).
18 Oct 2026 GPT-5.6 Sol (max): 5 new results (AutomationBench, GDP.pdf (AA), MLCR…).
16 Oct 2026 Kimi K2.5 (thinking): BenchLeader Index 59.4 → 58.9.

Rankings: Best LLM overall · Best LLM for agents · Best cheap LLMs