Compare/DeepSeek V3.1 Terminus (Reasoning) vs LongCat 2.0

DeepSeek V3.1 Terminus (Reasoning)vsLongCat 2.0

Side-by-side comparison of pricing, 12 benchmarks, and generation speed.

DeepSeek

DeepSeek V3.1 Terminus (Reasoning)

Input
$1.64/M
Output
$2.75/M
Speed
TTFT
LongCat

LongCat 2.0

Input
$0.75/M
Output
$2.95/M
Speed
44 tok/s
TTFT
2.56s

Winner by Category

Cheaper
LongCat 2.0
Faster (tok/s)
LongCat 2.0
Lower Latency
LongCat 2.0
Benchmarks (0-2)
LongCat 2.0

Pricing Comparison

MetricDeepSeek V3.1 Terminus (Reasoning)LongCat 2.0
Input ($/M tokens)$1.64$0.75
Output ($/M tokens)$2.75$2.95
Cost for 1M input + 100K output tokens:
DeepSeek V3.1 Terminus (Reasoning)$1.92
LongCat 2.0$1.04

Speed Comparison

Output Speed (tokens/s) — higher is better
DeepSeek V3.1 Terminus (Reasoning)
LongCat 2.0
44 tok/s
Time to First Token (seconds) — lower is better
DeepSeek V3.1 Terminus (Reasoning)
LongCat 2.0
2.56s

Editorial Analysis

Verdict. LongCat 2.0 takes the aggregate benchmark matchup 2–0 across 2 categories. Real workloads usually care about a handful of specific tasks — see the per-benchmark table above.

Pricing. Both models sit in the budget bracket for output-token pricing. At 0.9× the per-million-token cost, DeepSeek V3.1 Terminus (Reasoning) is meaningfully cheaper if your traffic is output-heavy (long completions, document generation, agent loops). DeepSeek V3.1 Terminus (Reasoning) makes more sense when output volume is low and absolute reasoning quality justifies the premium.

Strengths. DeepSeek V3.1 Terminus (Reasoning) is strongest on Coding Index (43.5), Intelligence Index (31.4). LongCat 2.0 leads on Coding Index (45.3), Intelligence Index (34.0).

Speed. Speed data is incomplete for this pair; benchmark and price should decide.

Provider. DeepSeek and LongCat sell to overlapping but distinct developer audiences: DeepSeek tends to ship frontier reasoning models with premium positioning, while LongCat often prices more aggressively. Your existing vendor relationships, billing, and SLA preferences may matter as much as the raw numbers above.

Workload cost. Workload scenarios (per million requests at 30M input + 15M output tokens): DeepSeek V3.1 Terminus (Reasoning) costs $90.45 ($1085/year); LongCat 2.0 costs $66.75 ($801/year). At a smaller 5M-input/2M-output scale (single-developer tool or prototype): DeepSeek V3.1 Terminus (Reasoning) ≈ $13.70/run, LongCat 2.0 ≈ $9.65/run. At agent/realtime scale (200M input / 100M output per million requests): DeepSeek V3.1 Terminus (Reasoning) ≈ $603/run, LongCat 2.0 ≈ $445/run. LongCat 2.0 becomes more attractive at higher volume — the absolute per-token pricing difference compounds when you ship at scale.

Recommendation. Both models have legitimate use cases — the right answer depends on whether you are optimizing for benchmark ceiling, latency, or unit cost. Start with the cheaper / faster model, evaluate against your specific task, and only switch if the upgrade shows a meaningful lift.

Head-to-head deltas

  • Aggregate benchmark score (sum across 12 categories, capped at 100): DeepSeek V3.1 Terminus (Reasoning) = 75, LongCat 2.0 = 79. Within 15% — effectively equivalent if both meet the threshold your product requires.

Benchmark Comparison

Data from Artificial Analysis API — 12 benchmarks

Intelligence Index
31.434.0
Coding Index
43.545.3
Math Index
GPQA Diamond
MMLU-Pro
LiveCodeBench
AIME 2025
MATH-500
Humanity's Last Exam
SciCode
IFBench
TerminalBench
DeepSeek V3.1 Terminus (Reasoning)0 wins
2 winsLongCat 2.0

Frequently Asked Questions

Which is cheaper, DeepSeek V3.1 Terminus (Reasoning) or LongCat 2.0?

LongCat 2.0 is cheaper overall. Its blended price (3:1 input/output ratio) is $1.30/M tokens vs $1.92/M for DeepSeek V3.1 Terminus (Reasoning).

Which model performs better on benchmarks?

LongCat 2.0 wins 2 out of 12 benchmarks compared to 0 for DeepSeek V3.1 Terminus (Reasoning). See the detailed benchmark chart above for per-category results.

Which is faster for real-time applications?

LongCat 2.0 generates tokens faster at 44 tok/s vs — tok/s. However, LongCat 2.0 has lower time-to-first-token (2.56s vs —s).

When should I use DeepSeek V3.1 Terminus (Reasoning) vs LongCat 2.0?

Choose based on your priorities: LongCat 2.0 for lower cost, LongCat 2.0 for stronger benchmark performance, and LongCat 2.0 for faster generation. For latency-sensitive apps, check the TTFT comparison above.