# LongCat-2.5 vs Seed 2.1 Pro

> Side-by-side benchmark comparison for LongCat-2.5 and Seed 2.1 Pro across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/longcat-2-5-vs-seed-2-1-pro
- Last updated: November 9, 2026

- Shared sourced benchmarks: 5
- HTML indexing: indexable
- Ranking lane: BenchAlign v5.8

## Quick Verdict

Treat this as a split decision: use the category and benchmark breakdown to decide which profile better matches your workload.

## Summary

- LongCat-2.5 and Seed 2.1 Pro are tied on overall score, so the decision depends on category fit rather than the headline number.
- The biggest single benchmark swing is Terminal-Bench 2.1 in Agentic, with scores of 88.4% and 71.0%.
- Seed 2.1 Pro is the cheaper option on output tokens, which matters if you expect large responses or heavy interactive use.
- LongCat-2.5 also has the larger context window at 1M.

## Model Snapshot

| Property | LongCat-2.5 | Seed 2.1 Pro |
|----------|----------|----------|
| Creator | Meituan | ByteDance |
| Type | Open Weight | Proprietary |
| Reasoning | Hybrid | Reasoning |
| Context | 1M | 256K |
| Overall Score | null | null |
| Benchmarks Covered | 22 | 11 |
| Pricing (input/output) | $0.30 / $1.20 | Pricing unavailable / Pricing unavailable |

## Category Breakdown

### Agentic

- Winner: Not comparable
- LongCat-2.5 public-lane score: Coming soon
- Seed 2.1 Pro public-lane score: Coming soon

| Benchmark | LongCat-2.5 | Seed 2.1 Pro | Winner |
|-----------|-----------|-----------|--------|
| Terminal-Bench 2.1 | 88.4% | 71.0% | LongCat-2.5 |
| Terminal-Bench 4.0 | 38.50% | Coming soon | Coming soon |
| BrowseComp | 91.9% | Coming soon | Coming soon |
| AutomationBench | 51.8% | Coming soon | Coming soon |
| HLE w/ tools | 63.1% | Coming soon | Coming soon |
| Agents' Last Exam | 38.5% | Coming soon | Coming soon |
| MCP Atlas | 83.1% | Coming soon | Coming soon |
| JobBench | 65.4% | Coming soon | Coming soon |
| skillsBench | 63.3% | Coming soon | Coming soon |
| SpreadsheetBench 2 | 34.9% | Coming soon | Coming soon |
| Claw-Eval | 78.3% | Coming soon | Coming soon |

### Coding

- Winner: Not comparable
- LongCat-2.5 public-lane score: Coming soon
- Seed 2.1 Pro public-lane score: Coming soon

| Benchmark | LongCat-2.5 | Seed 2.1 Pro | Winner |
|-----------|-----------|-----------|--------|
| Terminal-Bench 2.1 | 88.4% | 71.0% | LongCat-2.5 |
| ProgramBench | 25.5% | Coming soon | Coming soon |
| DeepSWE | 64.6% | Coming soon | Coming soon |
| PaperBench | 82.1% | Coming soon | Coming soon |
| SWE-Atlas Codebase QnA | 58.3% | Coming soon | Coming soon |
| NL2Repo | 60.5% | 47% | LongCat-2.5 |

### Multimodal & Grounded

- Winner: Not comparable
- LongCat-2.5 public-lane score: Coming soon
- Seed 2.1 Pro public-lane score: Coming soon

| Benchmark | LongCat-2.5 | Seed 2.1 Pro | Winner |
|-----------|-----------|-----------|--------|
| Vision2Web | 78.6% | Coming soon | Coming soon |
| CharXiv | 90.2% | 85.4% | LongCat-2.5 |
| MathVision w/ Python | 96.5% | Coming soon | Coming soon |
| Video-MME | 85.2% | 89.2% | Seed 2.1 Pro |
| MathVision | Coming soon | 92.6% | Coming soon |
| MMMU-Pro | Coming soon | 81.6% | Coming soon |
| ZeroBench | Coming soon | 18.0% | Coming soon |
| BabyVision | Coming soon | 73.7% | Coming soon |
| ERQA | Coming soon | 72.0% | Coming soon |

### Knowledge

- Winner: Not comparable
- LongCat-2.5 public-lane score: Coming soon
- Seed 2.1 Pro public-lane score: Coming soon

| Benchmark | LongCat-2.5 | Seed 2.1 Pro | Winner |
|-----------|-----------|-----------|--------|
| FrontierScience | 77% | Coming soon | Coming soon |
| SuperGPQA | Coming soon | 70.8% | Coming soon |

## FAQ

### Which is better overall, LongCat-2.5 or Seed 2.1 Pro?

LongCat-2.5 and Seed 2.1 Pro are tied on overall score in the current BenchLM data.

### How many benchmarks does LongCat-2.5 cover on BenchLM?

LongCat-2.5 currently has 22 sourced benchmark scores on BenchLM.

### How many benchmarks does Seed 2.1 Pro cover on BenchLM?

Seed 2.1 Pro currently has 11 sourced benchmark scores on BenchLM.

## Related Comparisons

- [LongCat-2.5 vs Seed 2.1 Turbo](/compare/longcat-2-5-vs-seed-2-1-turbo)
- [Seed 2.1 Pro vs Seed 2.1 Turbo](/compare/seed-2-1-pro-vs-seed-2-1-turbo)
- [LongCat-2.5 vs Claude Fable 5.2](/compare/claude-fable-5-2-vs-longcat-2-5)
- [Seed 2.1 Pro vs Claude Fable 5.2](/compare/claude-fable-5-2-vs-seed-2-1-pro)

## Explore More

- [LongCat-2.5 profile](/models/longcat-2-5)
- [Seed 2.1 Pro profile](/models/seed-2-1-pro)
- [Compare Pricing](/llm-pricing)
- [Alternative Finder](/tools/alternative-finder)
- [LLM Selector](/tools/llm-selector)
- [Overall Rankings](/best/overall)