Kimi K2.5 vs Seed 1.6 Flash

Side-by-side benchmark comparison across agentic, coding, multimodal, knowledge, reasoning, and math workflows.

Kimi K2.5 is clearly ahead on the aggregate, 60 to 56. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.

Kimi K2.5's sharpest advantage is in mathematics, where it averages 78.7 against 67.1. The single biggest benchmark swing on the page is SWE-bench Verified, 42 to 24. Seed 1.6 Flash does hit back in multimodal & grounded, so the answer changes if that is the part of the workload you care about most.

Kimi K2.5 is also the more expensive model on tokens at $0.50 input / $2.80 output per 1M tokens, versus $0.08 input / $0.30 output per 1M tokens for Seed 1.6 Flash. That is roughly 9.3x on output cost alone. Seed 1.6 Flash is the reasoning model in the pair, while Kimi K2.5 is not. That usually helps on harder chain-of-thought-heavy tests, but it can also mean more latency and more token spend in real use. Seed 1.6 Flash gives you the larger context window at 256K, compared with 128K for Kimi K2.5.

Quick Verdict

Pick Kimi K2.5 if you want the stronger benchmark profile. Seed 1.6 Flash only becomes the better choice if multimodal & grounded is the priority or you want the cheaper token bill.

Agentic

Seed 1.6 Flash

Kimi K2.5

52.3

Seed 1.6 Flash

54.5

51
Terminal-Bench 2.0
52
59
BrowseComp
62
49
OSWorld-Verified
52

Coding

Kimi K2.5

Kimi K2.5

38.9

Seed 1.6 Flash

27.6

69
HumanEval
59
42
SWE-bench Verified
24
37
LiveCodeBench
25
40
SWE-bench Pro
31

Multimodal & Grounded

Seed 1.6 Flash

Kimi K2.5

64.6

Seed 1.6 Flash

73.1

61
MMMU-Pro
74
69
OfficeQA Pro
72

Reasoning

Kimi K2.5

Kimi K2.5

71.7

Seed 1.6 Flash

66.8

74
SimpleQA
61
72
MuSR
59
81
BBH
75
67
LongBench v2
70
70
MRCRv2
74

Knowledge

Kimi K2.5

Kimi K2.5

57.2

Seed 1.6 Flash

47.3

77
MMLU
65
76
GPQA
64
74
SuperGPQA
62
72
OpenBookQA
60
74
MMLU-Pro
65
11
HLE
3
67
FrontierScience
57

Instruction Following

Kimi K2.5

Kimi K2.5

85

Seed 1.6 Flash

81

85
IFEval
81

Multilingual

Kimi K2.5

Kimi K2.5

79.8

Seed 1.6 Flash

72.8

83
MGSM
76
78
MMLU-ProX
71

Mathematics

Kimi K2.5

Kimi K2.5

78.7

Seed 1.6 Flash

67.1

77
AIME 2023
64
79
AIME 2024
66
78
AIME 2025
65
73
HMMT Feb 2023
60
75
HMMT Feb 2024
62
74
HMMT Feb 2025
61
76
BRUMO 2025
63
82
MATH-500
72

Frequently Asked Questions

Which is better, Kimi K2.5 or Seed 1.6 Flash?

Kimi K2.5 is ahead overall, 60 to 56. The biggest single separator in this matchup is SWE-bench Verified, where the scores are 42 and 24.

Which is better for knowledge tasks, Kimi K2.5 or Seed 1.6 Flash?

Kimi K2.5 has the edge for knowledge tasks in this comparison, averaging 57.2 versus 47.3. Inside this category, MMLU is the benchmark that creates the most daylight between them.

Which is better for coding, Kimi K2.5 or Seed 1.6 Flash?

Kimi K2.5 has the edge for coding in this comparison, averaging 38.9 versus 27.6. Inside this category, SWE-bench Verified is the benchmark that creates the most daylight between them.

Which is better for math, Kimi K2.5 or Seed 1.6 Flash?

Kimi K2.5 has the edge for math in this comparison, averaging 78.7 versus 67.1. Inside this category, AIME 2023 is the benchmark that creates the most daylight between them.

Which is better for reasoning, Kimi K2.5 or Seed 1.6 Flash?

Kimi K2.5 has the edge for reasoning in this comparison, averaging 71.7 versus 66.8. Inside this category, SimpleQA is the benchmark that creates the most daylight between them.

Which is better for agentic tasks, Kimi K2.5 or Seed 1.6 Flash?

Seed 1.6 Flash has the edge for agentic tasks in this comparison, averaging 54.5 versus 52.3. Inside this category, BrowseComp is the benchmark that creates the most daylight between them.

Which is better for multimodal and grounded tasks, Kimi K2.5 or Seed 1.6 Flash?

Seed 1.6 Flash has the edge for multimodal and grounded tasks in this comparison, averaging 73.1 versus 64.6. Inside this category, MMMU-Pro is the benchmark that creates the most daylight between them.

Which is better for instruction following, Kimi K2.5 or Seed 1.6 Flash?

Kimi K2.5 has the edge for instruction following in this comparison, averaging 85 versus 81. Inside this category, IFEval is the benchmark that creates the most daylight between them.

Which is better for multilingual tasks, Kimi K2.5 or Seed 1.6 Flash?

Kimi K2.5 has the edge for multilingual tasks in this comparison, averaging 79.8 versus 72.8. Inside this category, MGSM is the benchmark that creates the most daylight between them.

Last updated: March 12, 2026

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