Aion-2.0 vs Seed 1.6 Flash

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

Aion-2.0 has the cleaner overall profile here, landing at 58 versus 56. It is a real lead, but still close enough that category-level strengths matter more than the headline number.

Aion-2.0's sharpest advantage is in instruction following, where it averages 93 against 81. The single biggest benchmark swing on the page is SimpleQA, 76 to 61. 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.

Aion-2.0 is also the more expensive model on tokens at $0.80 input / $1.60 output per 1M tokens, versus $0.08 input / $0.30 output per 1M tokens for Seed 1.6 Flash. That is roughly 5.3x on output cost alone. Seed 1.6 Flash is the reasoning model in the pair, while Aion-2.0 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 Aion-2.0.

Quick Verdict

Pick Aion-2.0 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

Aion-2.0

51.7

Seed 1.6 Flash

54.5

48
Terminal-Bench 2.0
52
60
BrowseComp
62
50
OSWorld-Verified
52

Coding

Aion-2.0

Aion-2.0

33.2

Seed 1.6 Flash

27.6

66
HumanEval
59
35
SWE-bench Verified
24
29
LiveCodeBench
25
37
SWE-bench Pro
31

Multimodal & Grounded

Seed 1.6 Flash

Aion-2.0

66

Seed 1.6 Flash

73.1

61
MMMU-Pro
74
72
OfficeQA Pro
72

Reasoning

Aion-2.0

Aion-2.0

70.3

Seed 1.6 Flash

66.8

76
SimpleQA
61
74
MuSR
59
76
BBH
75
64
LongBench v2
70
65
MRCRv2
74

Knowledge

Aion-2.0

Aion-2.0

54

Seed 1.6 Flash

47.3

78
MMLU
65
77
GPQA
64
75
SuperGPQA
62
75
OpenBookQA
60
67
MMLU-Pro
65
5
HLE
3
66
FrontierScience
57

Instruction Following

Aion-2.0

Aion-2.0

93

Seed 1.6 Flash

81

93
IFEval
81

Multilingual

Aion-2.0

Aion-2.0

78.1

Seed 1.6 Flash

72.8

80
MGSM
76
77
MMLU-ProX
71

Mathematics

Aion-2.0

Aion-2.0

72.1

Seed 1.6 Flash

67.1

74
AIME 2023
64
76
AIME 2024
66
75
AIME 2025
65
70
HMMT Feb 2023
60
72
HMMT Feb 2024
62
71
HMMT Feb 2025
61
73
BRUMO 2025
63
71
MATH-500
72

Frequently Asked Questions

Which is better, Aion-2.0 or Seed 1.6 Flash?

Aion-2.0 is ahead overall, 58 to 56. The biggest single separator in this matchup is SimpleQA, where the scores are 76 and 61.

Which is better for knowledge tasks, Aion-2.0 or Seed 1.6 Flash?

Aion-2.0 has the edge for knowledge tasks in this comparison, averaging 54 versus 47.3. Inside this category, OpenBookQA is the benchmark that creates the most daylight between them.

Which is better for coding, Aion-2.0 or Seed 1.6 Flash?

Aion-2.0 has the edge for coding in this comparison, averaging 33.2 versus 27.6. Inside this category, SWE-bench Verified is the benchmark that creates the most daylight between them.

Which is better for math, Aion-2.0 or Seed 1.6 Flash?

Aion-2.0 has the edge for math in this comparison, averaging 72.1 versus 67.1. Inside this category, AIME 2023 is the benchmark that creates the most daylight between them.

Which is better for reasoning, Aion-2.0 or Seed 1.6 Flash?

Aion-2.0 has the edge for reasoning in this comparison, averaging 70.3 versus 66.8. Inside this category, SimpleQA is the benchmark that creates the most daylight between them.

Which is better for agentic tasks, Aion-2.0 or Seed 1.6 Flash?

Seed 1.6 Flash has the edge for agentic tasks in this comparison, averaging 54.5 versus 51.7. Inside this category, Terminal-Bench 2.0 is the benchmark that creates the most daylight between them.

Which is better for multimodal and grounded tasks, Aion-2.0 or Seed 1.6 Flash?

Seed 1.6 Flash has the edge for multimodal and grounded tasks in this comparison, averaging 73.1 versus 66. Inside this category, MMMU-Pro is the benchmark that creates the most daylight between them.

Which is better for instruction following, Aion-2.0 or Seed 1.6 Flash?

Aion-2.0 has the edge for instruction following in this comparison, averaging 93 versus 81. Inside this category, IFEval is the benchmark that creates the most daylight between them.

Which is better for multilingual tasks, Aion-2.0 or Seed 1.6 Flash?

Aion-2.0 has the edge for multilingual tasks in this comparison, averaging 78.1 versus 72.8. Inside this category, MMLU-ProX is the benchmark that creates the most daylight between them.

Last updated: March 12, 2026

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