Seed 1.6 Flash vs Gemini 2.5 Flash

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

Seed 1.6 Flash is clearly ahead on the aggregate, 56 to 49. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.

Seed 1.6 Flash's sharpest advantage is in agentic, where it averages 54.5 against 46.5. The single biggest benchmark swing on the page is HumanEval, 59 to 42.

Gemini 2.5 Flash is also the more expensive model on tokens at $0.15 input / $0.60 output per 1M tokens, versus $0.08 input / $0.30 output per 1M tokens for Seed 1.6 Flash. That is roughly 2.0x on output cost alone. Seed 1.6 Flash is the reasoning model in the pair, while Gemini 2.5 Flash 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. Gemini 2.5 Flash gives you the larger context window at 1M, compared with 256K for Seed 1.6 Flash.

Quick Verdict

Pick Seed 1.6 Flash if you want the stronger benchmark profile. Gemini 2.5 Flash only becomes the better choice if you need the larger 1M context window or you would rather avoid the extra latency and token burn of a reasoning model.

Agentic

Seed 1.6 Flash

Seed 1.6 Flash

54.5

Gemini 2.5 Flash

46.5

52
Terminal-Bench 2.0
44
62
BrowseComp
58
52
OSWorld-Verified
41

Coding

Seed 1.6 Flash

Seed 1.6 Flash

27.6

Gemini 2.5 Flash

21.7

59
HumanEval
42
24
SWE-bench Verified
23
25
LiveCodeBench
18
31
SWE-bench Pro
25

Multimodal & Grounded

Seed 1.6 Flash

Seed 1.6 Flash

73.1

Gemini 2.5 Flash

67.7

74
MMMU-Pro
69
72
OfficeQA Pro
66

Reasoning

Seed 1.6 Flash

Seed 1.6 Flash

66.8

Gemini 2.5 Flash

59.2

61
SimpleQA
48
59
MuSR
46
75
BBH
75
70
LongBench v2
68
74
MRCRv2
68

Knowledge

Seed 1.6 Flash

Seed 1.6 Flash

47.3

Gemini 2.5 Flash

40.5

65
MMLU
50
64
GPQA
49
62
SuperGPQA
47
60
OpenBookQA
45
65
MMLU-Pro
64
3
HLE
1
57
FrontierScience
49

Instruction Following

Seed 1.6 Flash

Seed 1.6 Flash

81

Gemini 2.5 Flash

79

81
IFEval
79

Multilingual

Seed 1.6 Flash

Seed 1.6 Flash

72.8

Gemini 2.5 Flash

70.8

76
MGSM
74
71
MMLU-ProX
69

Mathematics

Seed 1.6 Flash

Seed 1.6 Flash

67.1

Gemini 2.5 Flash

59.4

64
AIME 2023
50
66
AIME 2024
52
65
AIME 2025
51
60
HMMT Feb 2023
46
62
HMMT Feb 2024
48
61
HMMT Feb 2025
47
63
BRUMO 2025
49
72
MATH-500
72

Frequently Asked Questions

Which is better, Seed 1.6 Flash or Gemini 2.5 Flash?

Seed 1.6 Flash is ahead overall, 56 to 49. The biggest single separator in this matchup is HumanEval, where the scores are 59 and 42.

Which is better for knowledge tasks, Seed 1.6 Flash or Gemini 2.5 Flash?

Seed 1.6 Flash has the edge for knowledge tasks in this comparison, averaging 47.3 versus 40.5. Inside this category, MMLU is the benchmark that creates the most daylight between them.

Which is better for coding, Seed 1.6 Flash or Gemini 2.5 Flash?

Seed 1.6 Flash has the edge for coding in this comparison, averaging 27.6 versus 21.7. Inside this category, HumanEval is the benchmark that creates the most daylight between them.

Which is better for math, Seed 1.6 Flash or Gemini 2.5 Flash?

Seed 1.6 Flash has the edge for math in this comparison, averaging 67.1 versus 59.4. Inside this category, AIME 2023 is the benchmark that creates the most daylight between them.

Which is better for reasoning, Seed 1.6 Flash or Gemini 2.5 Flash?

Seed 1.6 Flash has the edge for reasoning in this comparison, averaging 66.8 versus 59.2. Inside this category, SimpleQA is the benchmark that creates the most daylight between them.

Which is better for agentic tasks, Seed 1.6 Flash or Gemini 2.5 Flash?

Seed 1.6 Flash has the edge for agentic tasks in this comparison, averaging 54.5 versus 46.5. Inside this category, OSWorld-Verified is the benchmark that creates the most daylight between them.

Which is better for multimodal and grounded tasks, Seed 1.6 Flash or Gemini 2.5 Flash?

Seed 1.6 Flash has the edge for multimodal and grounded tasks in this comparison, averaging 73.1 versus 67.7. Inside this category, OfficeQA Pro is the benchmark that creates the most daylight between them.

Which is better for instruction following, Seed 1.6 Flash or Gemini 2.5 Flash?

Seed 1.6 Flash has the edge for instruction following in this comparison, averaging 81 versus 79. Inside this category, IFEval is the benchmark that creates the most daylight between them.

Which is better for multilingual tasks, Seed 1.6 Flash or Gemini 2.5 Flash?

Seed 1.6 Flash has the edge for multilingual tasks in this comparison, averaging 72.8 versus 70.8. Inside this category, MGSM is the benchmark that creates the most daylight between them.

Last updated: March 12, 2026

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