How do Claude Opus 5.5 and DeepSeek V4.1 Flash compare on coding benchmarks?

The comparison table shows SWE-bench, SWE-Pro, SWE-Atlas, Terminal-Bench, DeepSWE, and coding agent index scores for both Claude Opus 5.5 and DeepSeek V4.1 Flash when publicly disclosed.

LLM Comparison

Claude Opus 5.5 vs DeepSeek V4.1 Flash: benchmark scores, pricing & comparison.

Q: Which is better: Claude Opus 5.5 or DeepSeek V4.1 Flash?

AskClash compares Claude Opus 5.5 and DeepSeek V4.1 Flash side by side across SWE-bench, GPQA, HLE, Terminal-Bench, coding agent scores, token pricing, AskClash ACB, and context window so you can see which model wins on each benchmark.

Side-by-side Claude Opus 5.5 vs DeepSeek V4.1 Flash comparison across SWE-bench, GPQA, HLE, Terminal-Bench, coding agent scores, token pricing, context window, and AskClash RWT. Green marks the winner on each benchmark.

Open live leaderboard Claude Opus 5.5 model page DeepSeek V4.1 Flash model page

Rank #12 vs #18AskClash overall scores 64.5 vs 63.6.

Pricing $4.00/$20.0 vs $0.15/$0.60Input and output token prices per 1M tokens when published.

Proprietary vs APIAnthropic vs DeepSeek.

Claude Opus 5.5 vs DeepSeek V4.1 Flash benchmark comparison

Green cells highlight the winning model for each metric. Scores are cached from the AskClash LLM leaderboard snapshot.

Metric	Claude Opus 5.5	DeepSeek V4.1 Flash
Overall Score	64.5	63.6
Leaderboard Rank	#12	#18
ACB	61.7	63.0
HLE	67.7	36.8
GPQA	—	90.9
SWE-Pro	89.9	—
Terminal-Bench	—	90.6
DeepSWE	74.2	74.2
GDPval-AA	1846.2	1600.0
Finance Agent	—	53.5
MMMU-Pro	87.7	77.0
Input Price (per 1M tokens)	$4.00	$0.15
Output Price (per 1M tokens)	$20.0	$0.60
Context Window	1M	1M
Benchmarks Published	7	9

Claude Opus 5.5 vs DeepSeek V4.1 Flash head-to-head charts

Claude Opus 5.5 leads 4 and DeepSeek V4.1 Flash leads 1 of 6 shared benchmarks. DeepSeek V4.1 Flash is cheaper on a defined 1M-input / 200K-output workload. Charts show only benchmarks both models publish.

Claude Opus 5.5DeepSeek V4.1 Flash

Overall

64.5Claude Opus 5.5

63.6DeepSeek V4.1 Flash

ACB

61.7Claude Opus 5.5

63.0DeepSeek V4.1 Flash

HLE

67.7Claude Opus 5.5

36.8DeepSeek V4.1 Flash

DeepSWE

74.2Claude Opus 5.5

74.2DeepSeek V4.1 Flash

GDPval-AA

1846.2Claude Opus 5.5

1600.0DeepSeek V4.1 Flash

MMMU-Pro

87.7Claude Opus 5.5

77.0DeepSeek V4.1 Flash

Claude Opus 5.5

Input$4.00

Output$20.0

Workload$8.00

Context1M

DeepSeek V4.1 Flash

Input$0.15

Output$0.60

Workload$0.27

Context1M

Workload = published cost of 1M input + 200K output tokens. Open the live leaderboard for interactive compare charts.

More Claude Opus 5.5 and DeepSeek V4.1 Flash comparisons

Explore how Claude Opus 5.5 and DeepSeek V4.1 Flash stack up against other top-ranked LLMs.

Claude Fable 5.1 vs Claude Opus 5.5 Claude Fable 5.1 vs DeepSeek V4.1 Flash Claude Fable 5 vs Claude Opus 5.5 Claude Fable 5 vs DeepSeek V4.1 Flash Claude Opus 5 vs Claude Opus 5.5 Claude Opus 5 vs DeepSeek V4.1 Flash GPT-5.6 Sol vs Claude Opus 5.5 GPT-5.6 Sol vs DeepSeek V4.1 Flash Qwen3.8 Max vs Claude Opus 5.5 Qwen3.8 Max vs DeepSeek V4.1 Flash

How to read this comparison

Benchmark scores

Higher is better for all benchmark scores (SWE-bench, GPQA, HLE, Terminal-Bench, etc.). Green marks the model with the higher score.

Token pricing

Lower is better for input and output prices. Green marks the cheaper model per 1M tokens.

Coverage matters

Models with fewer disclosed benchmark cells may have inflated percentile scores. Check the benchmark cell count for context.

This comparison page is generated from the AskClash LLM leaderboard cache. Open the live leaderboard for real-time scores and interactive filtering.