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GPT-5.5 vs SWE-2 Flash

GPT-5.5 and SWE-2 Flash are closely matched at 46.7 and 43.8 on the LLM Stats Score.

OpenAI · Cognition · Updated for 2026

Which is better?

GPT-5.5 and SWE-2 Flash are closely matched on the overall LLM Stats Score at 46.7 and 43.8.

The models split the 2 individual benchmarks reported for both models evenly.

Based on current LLM Stats indexes, shared benchmarks, pricing, and model metadata for 2026.

Choose GPT-5.5

  • you want predictable pricing at $5.00/M input and $30.00/M output

Choose SWE-2 Flash

  • you want the most recent training data — it shipped Nov 2026

At a glance

The differences that matter most.

GPT-5.5
OpenAI
SWE-2 Flash
Cognition
Core performance indexes
LLM Stats Score
46.7
#43
43.8
#58
Reasoning
46.5
#35
42.6
#61
Coding
34.5
#39
33.0
#44
Agents
30.1
#51
30.1
#50
Cost, coverage & limits
Benchmark wins
1 of 2
1 of 2
Input price
$5.00 / M
— / M
Output price
$30.00 / M
— / M
Context window
1,050,000
—

Capability indexes

Additional strengths measured across groups of related public benchmarks

1 shared
Index
GPT-5.5
SWE-2 Flash
Tool use
27.1#37
23.0#58
Conservative TrueSkill rating · higher is betterHow scores work

Individual benchmarks

28 reported for GPT-5.5 · 7 for SWE-2 Flash

2 shared

GPT-5.5 outperforms in 1 benchmarks (DeepSWE 1.1), while SWE-2 Flash is better at 1 benchmark (FrontierCode 1.1).

Both models are evenly matched across the benchmarks.

Thu Nov 12 2026 • llm-stats.com

Human preference

Blind head-to-head votes and playground preference scores

Context Window

Maximum input and output token capacity

Only GPT-5.5 specifies input context (1,050,000 tokens). Only GPT-5.5 specifies output context (128,000 tokens).

OpenAI
GPT-5.5
Input1,050,000 tokens
Output128,000 tokens
Cognition
SWE-2 Flash
Input- tokens
Output- tokens
Thu Nov 12 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

GPT-5.5 supports multimodal inputs, whereas SWE-2 Flash does not.

GPT-5.5 can handle both text and other forms of data like images, making it suitable for multimodal applications.

GPT-5.5

Text
Images
Audio
Video

SWE-2 Flash

Text
Images
Audio
Video

License

Usage and distribution terms

Both models are licensed under proprietary licenses.

Both models have usage restrictions defined by their respective organizations.

GPT-5.5

Proprietary

Closed source

SWE-2 Flash

Proprietary

Closed source

Release Timeline

When each model was launched

GPT-5.5 was released on 2026-04-23, while SWE-2 Flash was released on 2026-11-04.

SWE-2 Flash is 7 months newer than GPT-5.5.

GPT-5.5

Apr 23, 2026

6 months ago

SWE-2 Flash

Nov 4, 2026

1 weeks ago

6mo newer

Knowledge Cutoff

When training data ends

GPT-5.5 has a documented knowledge cutoff of 2025-12-01, while SWE-2 Flash's cutoff date is not specified.

We can confirm GPT-5.5's training data extends to 2025-12-01, but cannot make a direct comparison without SWE-2 Flash's cutoff date.

GPT-5.5

Dec 2025

SWE-2 Flash

—

Outputs Comparison

Notice missing or incorrect data?

Judge for yourself.

Run your own prompts against GPT-5.5 and SWE-2 Flash side-by-side, then vote on the output you prefer.

GPT-5.5
✓ Preferred
SWE-2 Flash
Open in Playground

FAQ

Common questions about GPT-5.5 vs SWE-2 Flash.

Which is better, GPT-5.5 or SWE-2 Flash?

GPT-5.5 and SWE-2 Flash are closely matched on the LLM Stats Score at 46.7 and 43.8. GPT-5.5 is made by OpenAI and SWE-2 Flash is made by Cognition. The best choice depends on your use case — compare their capability indexes, individual benchmarks, pricing, and limits above.

How does GPT-5.5 compare to SWE-2 Flash in benchmarks?

GPT-5.5 scores Tau2 Telecom: 98.0%, ARC-AGI: 95.0%, GPQA: 93.6%, ARC-AGI v2: 85.0%, GDPval-MM: 84.9%. SWE-2 Flash scores Terminal-Bench 2.1: 89.2%, DeepSWE 1.1: 60.1%, SWE Atlas - Codebase QnA: 50.0%, FrontierCode 1.1: 45.5%, ExploitBench: 34.8%.

What are the context window sizes for GPT-5.5 and SWE-2 Flash?

GPT-5.5 supports 1.1M tokens and SWE-2 Flash supports an unknown number of tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

What are the main differences between GPT-5.5 and SWE-2 Flash?

Key differences include LLM Stats Score (46.7 vs 43.8), multimodal support (yes vs no). See the full comparison above for benchmark-by-benchmark results.

Who makes GPT-5.5 and SWE-2 Flash?

GPT-5.5 is developed by OpenAI and SWE-2 Flash is developed by Cognition.

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