# DeepSeek V4 Flash vs GPT-5.5 Instant

> DeepSeek V4 Flash is the stronger model overall, scoring 53.6 to 42.5 on the Noometry Index.

- Canonical page: https://noometry.com/compare/deepseek-v4-flash-vs-gpt-5-5-instant
- Last updated: 2026-10-10
- Shared benchmarks: 25

## Summary

- They share 25 benchmarks with published results for both. DeepSeek V4 Flash scores higher in 8 categories and GPT-5.5 Instant in 0 categories; 5 gaps are clear of the uncertainty.
- The widest gap is in math, where DeepSeek V4 Flash leads 60.0 to 26.1.
- The biggest single-benchmark swing is FrontierMath (Tiers 1-3): 57.5% for DeepSeek V4 Flash and 26.3% for GPT-5.5 Instant.
- DeepSeek V4 Flash has downloadable open weights; the other is API-only.

## Snapshot

| | DeepSeek V4 Flash | GPT-5.5 Instant |
|---|---|---|
| Provider | DeepSeek | OpenAI |
| Noometry Index | 53.6 | 42.5 |
| Rank | 32 | 99 |
| Context | 1M | — |
| Input $/M | $0.15 | — |
| Output $/M | $0.60 | — |
| Weights | Open | Proprietary |

## Coding

- DeepSeek V4 Flash: 47.6 (#56)
- GPT-5.5 Instant: 43.7 (#73)

| Benchmark | DeepSeek V4 Flash | GPT-5.5 Instant |
|---|---|---|
| SciCode | 49.9% | 48.6% |
| LMArena Coding | 1457 | 1433 |
| FrontierCode | 18.8% | — |
| LMArena WebDev | 1581 | — |
| WeirdML | 63% | — |
| ALE-Bench | 1,306 | — |

## Reasoning

- DeepSeek V4 Flash: 53.7 (#25)
- GPT-5.5 Instant: 24.2 (#149)

| Benchmark | DeepSeek V4 Flash | GPT-5.5 Instant |
|---|---|---|
| CritPt | 16.6% | 0% |
| Chess Puzzles | 33% | 12% |
| LMArena Hard Prompts | 1443 | 1426 |
| Epoch Capabilities Index | 154.51 | 142.48 |
| ARC-AGI-2 | 61.4% | — |
| SimpleBench | 61.1% | — |
| Kagi LLM Benchmark | 52.2% | — |
| NYT Connections (extended) | 89.6% | — |
| ARC-AGI-1 | 89% | — |
| Mystery Game Puzzles | 34% | — |
| DTBench | 90.9% | — |
| LMCA | 41.7% | — |

## Math

- DeepSeek V4 Flash: 60.0 (#31)
- GPT-5.5 Instant: 26.1 (#241)

| Benchmark | DeepSeek V4 Flash | GPT-5.5 Instant |
|---|---|---|
| FrontierMath (Tiers 1-3) | 57.5% | 26.3% |
| FrontierMath Tier 4 | 24.4% | 2.4% |
| OTIS Mock AIME 2024-2025 | 94.4% | 68.1% |
| LMArena Math | 1427 | 1420 |
| MathArena Final-Answer Competitions | 76.5% | — |
| ProofBench | 56% | — |

## Knowledge

- DeepSeek V4 Flash: 55.5 (#43)
- GPT-5.5 Instant: 48.9 (#68)

| Benchmark | DeepSeek V4 Flash | GPT-5.5 Instant |
|---|---|---|
| GPQA Diamond | 91% | 82.5% |
| LMArena Expert | 1441 | 1409 |
| SimpleQA Verified | 33.6% | — |

## Multimodal

- DeepSeek V4 Flash: —
- GPT-5.5 Instant: 39.3 (#48)

| Benchmark | DeepSeek V4 Flash | GPT-5.5 Instant |
|---|---|---|
| LMArena Vision | — | 1250 |
| LMArena Document | — | 1403 |

## Multilingual

- DeepSeek V4 Flash: 53.2 (#71)
- GPT-5.5 Instant: 53.0 (#76)

| Benchmark | DeepSeek V4 Flash | GPT-5.5 Instant |
|---|---|---|
| LMArena Non-English | 1420 | 1417 |
| LMArena Chinese | 1467 | 1457 |
| LMArena French | 1438 | 1428 |
| LMArena German | 1418 | 1410 |
| LMArena Japanese | 1403 | 1408 |
| LMArena Korean | 1383 | 1393 |
| LMArena Russian | 1428 | 1430 |
| LMArena Spanish | 1437 | 1430 |

## Instruction Following

- DeepSeek V4 Flash: 75.1 (#76)
- GPT-5.5 Instant: 74.4 (#94)

| Benchmark | DeepSeek V4 Flash | GPT-5.5 Instant |
|---|---|---|
| LMArena Instruction Following | 1421 | 1407 |

## Long Context

- DeepSeek V4 Flash: 43.8 (#81)
- GPT-5.5 Instant: 43.4 (#92)

| Benchmark | DeepSeek V4 Flash | GPT-5.5 Instant |
|---|---|---|
| LMArena Longer Query | 1435 | 1422 |

## Writing & Preference

- DeepSeek V4 Flash: 64.0 (#59)
- GPT-5.5 Instant: 62.0 (#81)

| Benchmark | DeepSeek V4 Flash | GPT-5.5 Instant |
|---|---|---|
| LMArena Text | 1432 | 1419 |
| LMArena Creative Writing | 1403 | 1420 |
| LMArena Multi-Turn | 1449 | 1434 |
| EQ-Bench Creative Writing | 1559 | — |

## FAQ

### Is DeepSeek V4 Flash better than GPT-5.5 Instant?

DeepSeek V4 Flash is the stronger model overall, scoring 53.6 to 42.5 on the Noometry Index.

### Is DeepSeek V4 Flash or GPT-5.5 Instant better for coding?

DeepSeek V4 Flash scores higher on coding benchmarks: 47.6 versus 43.7 in the Noometry coding category.

### How many benchmarks do DeepSeek V4 Flash and GPT-5.5 Instant share?

25 benchmarks have published results for both models. DeepSeek V4 Flash has 41 scored results on Noometry and GPT-5.5 Instant has 27.