# Gemini 3.8 Flash vs Seed 2.1 Pro

> Side-by-side benchmark comparison for Gemini 3.8 Flash and Seed 2.1 Pro across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/gemini-3-8-flash-vs-seed-2-1-pro
- Last updated: September 10, 2026

- Shared sourced benchmarks: 2
- HTML indexing: indexable
- Ranking lane: BenchAlign v5

## Quick Verdict

Evidence is too thin for a benchmark verdict: Gemini 3.8 Flash and Seed 2.1 Pro share only 2 sourced benchmark rows.

## Summary

- Only 2 shared sourced benchmark rows are available. That is not enough for a broad capability verdict, so this mirror does not name an overall winner.
- Seed 2.1 Pro has the lower published output-token price.
- Gemini 3.8 Flash has the larger published context window at 1M.

## Model Snapshot

| Property | Gemini 3.8 Flash | Seed 2.1 Pro |
|----------|----------|----------|
| Creator | Google | ByteDance |
| Type | Proprietary | Proprietary |
| Reasoning | Reasoning | Reasoning |
| Context | 1M | 256K |
| Independent public score (not head-to-head) | 75.61 | null |
| Benchmarks Covered | 19 | 11 |
| Pricing (input/output) | $0.75 / $3.75 | Pricing unavailable / Pricing unavailable |

## Category Breakdown

### Agentic

- Winner: Insufficient shared evidence
- Gemini 3.8 Flash public-lane score: 66.3 (Supported · #10/152)
- Seed 2.1 Pro public-lane score: Coming soon

| Benchmark | Gemini 3.8 Flash | Seed 2.1 Pro | Winner |
|-----------|-----------|-----------|--------|
| Finance Agent v2 | 61.4% | Coming soon | Coming soon |
| Terminal-Bench 2.1 | 89.4% | 71.0% | Gemini 3.8 Flash |
| Terminal-Bench 4.0 | 19.10% | Coming soon | Coming soon |
| OSWorld 2.0 | 59.0% | Coming soon | Coming soon |
| Terminal-Bench 2.1 (Vals) | 81.3% | Coming soon | Coming soon |

### Coding

- Winner: Insufficient shared evidence
- Gemini 3.8 Flash public-lane score: 66.6 (Supported · #10/151)
- Seed 2.1 Pro public-lane score: Coming soon

| Benchmark | Gemini 3.8 Flash | Seed 2.1 Pro | Winner |
|-----------|-----------|-----------|--------|
| DeepSWE | 73.8% | Coming soon | Coming soon |
| Terminal-Bench 2.1 | 89.4% | 71.0% | Gemini 3.8 Flash |
| cursorBench32 | 69.2% | Coming soon | Coming soon |
| LiveCodeBench (Vals) | 89.5% | Coming soon | Coming soon |
| SWE-bench (Vals) | 80.0% | Coming soon | Coming soon |
| FrontierSWE v2 | 19.6% | Coming soon | Coming soon |
| NL2Repo | Coming soon | 47% | Coming soon |

### Multimodal & Grounded

- Winner: Insufficient shared evidence
- Gemini 3.8 Flash public-lane score: 82.8 (#8/48)
- Seed 2.1 Pro public-lane score: Coming soon

| Benchmark | Gemini 3.8 Flash | Seed 2.1 Pro | Winner |
|-----------|-----------|-----------|--------|
| CharXiv w/o tools | 86.2% | Coming soon | Coming soon |
| LVBench | 87.1% | Coming soon | Coming soon |
| 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 |
| CharXiv | Coming soon | 85.4% | Coming soon |
| ERQA | Coming soon | 72.0% | Coming soon |
| Video-MME | Coming soon | 89.2% | Coming soon |

### Reasoning

- Winner: Insufficient shared evidence
- Gemini 3.8 Flash public-lane score: 76.9 (#8/20)
- Seed 2.1 Pro public-lane score: Coming soon

### Knowledge

- Winner: Insufficient shared evidence
- Gemini 3.8 Flash public-lane score: 74.9 (Supported · #6/183)
- Seed 2.1 Pro public-lane score: Coming soon

| Benchmark | Gemini 3.8 Flash | Seed 2.1 Pro | Winner |
|-----------|-----------|-----------|--------|
| HLE-Verified | 54.9% | Coming soon | Coming soon |
| LABBench2 | 86.2% | Coming soon | Coming soon |
| BioMysteryBench (human-solvable) | 88.8% | Coming soon | Coming soon |
| BioMysteryBench (human-difficult) | 56.5% | Coming soon | Coming soon |
| GPQA Diamond (Vals) | 94.4% | Coming soon | Coming soon |
| MMLU-Pro (Vals) | 90.2% | Coming soon | Coming soon |
| SuperGPQA | Coming soon | 70.8% | Coming soon |

## FAQ

### Is there enough evidence to pick between Gemini 3.8 Flash and Seed 2.1 Pro?

Not yet. The models share only 2 sourced benchmark rows, so this mirror reports the available measurements and metadata without naming a broad winner.

### What can I compare safely on this page?

Published pricing, context windows, model type, and individual shared benchmark rows are directly comparable. Independent overall scores and non-overlapping benchmark coverage are labeled separately and should not be read as a controlled head-to-head result.

## Related Comparisons

- [Gemini 3.8 Flash vs Gemini 3.8 Flash Cyber](/compare/gemini-3-8-flash-vs-gemini-3-8-flash-cyber)
- [Seed 2.1 Pro vs Gemini 3.8 Flash Cyber](/compare/gemini-3-8-flash-cyber-vs-seed-2-1-pro)
- [Gemini 3.8 Flash vs Seed 2.1 Turbo](/compare/gemini-3-8-flash-vs-seed-2-1-turbo)
- [Seed 2.1 Pro vs Seed 2.1 Turbo](/compare/seed-2-1-pro-vs-seed-2-1-turbo)

## Explore More

- [Gemini 3.8 Flash profile](/models/gemini-3-8-flash)
- [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)