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Gemini 3.8 Flash vs GPT-5.5 Pro

Gemini 3.8 Flash and GPT-5.5 Pro are closely matched at 51.2 and 44.9 on the LLM Stats Score. Gemini 3.8 Flash is 45.0x cheaper per token.

Google · OpenAI · Updated for 2026

Which is better?

Gemini 3.8 Flash and GPT-5.5 Pro are closely matched on the overall LLM Stats Score at 51.2 and 44.9.

On price, Gemini 3.8 Flash is roughly 45.0x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.

GPT-5.5 Pro also accepts a larger context window (1,050,000 input tokens), making it the stronger choice for long documents and large codebases.

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

Choose Gemini 3.8 Flash

  • cost matters — it's about 45.0x cheaper per token
  • you want the most recent training data — it shipped Sep 2026

Choose GPT-5.5 Pro

  • you process long inputs — it offers a 1,050,000 token context window

At a glance

The differences that matter most.

Gemini 3.8 Flash
Google
GPT-5.5 Pro
OpenAI
Core performance indexes
LLM Stats Score
51.2
#12
44.9
#34
Reasoning
47.5
#23
44.7
#31
Agents
36.1
#16
28.3
#39
Cost, coverage & limits
Benchmark wins
—
—
Input price
$0.75 / M
$30.00 / M
Output price
$3.75 / M
$180.00 / M
Context window
1,048,576
1,050,000

Individual benchmarks

13 reported for Gemini 3.8 Flash · 5 for GPT-5.5 Pro

No common benchmarks found

Gemini 3.8 Flash and GPT-5.5 Prodon't have any common benchmark datasets to compare. They may have been evaluated on different testing suites.

Human preference

Blind head-to-head votes and playground preference scores

Pricing Analysis

Price comparison per million tokens

Gemini 3.8 Flash costs less

For input processing, Gemini 3.8 Flash ($0.75/1M tokens) is 40.0x cheaper than GPT-5.5 Pro ($30.00/1M tokens).

For output processing, Gemini 3.8 Flash ($3.75/1M tokens) is 48.0x cheaper than GPT-5.5 Pro ($180.00/1M tokens).

In conclusion, GPT-5.5 Pro is more expensive than Gemini 3.8 Flash.*

* Using a 3:1 ratio of input to output tokens

Lowest available price from all providers
Thu Sep 10 2026 • llm-stats.com
Google
Gemini 3.8 Flash
Input tokens$0.75
Output tokens$3.75
Best providerGoogle
OpenAI
GPT-5.5 Pro
Input tokens$30.00
Output tokens$180.00
Best providerOpenAI
Notice missing or incorrect data?Start an Issue→

Context Window

Maximum input and output token capacity

GPT-5.5 Pro accepts 1,050,000 input tokens compared to Gemini 3.8 Flash's 1,048,576 tokens. GPT-5.5 Pro can generate longer responses up to 128,000 tokens, while Gemini 3.8 Flash is limited to 65,536 tokens.

Google
Gemini 3.8 Flash
Input1,048,576 tokens
Output65,536 tokens
OpenAI
GPT-5.5 Pro
Input1,050,000 tokens
Output128,000 tokens
Thu Sep 10 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

Both Gemini 3.8 Flash and GPT-5.5 Pro support multimodal inputs.

They are both capable of processing various types of data, offering versatility in application.

Gemini 3.8 Flash

Text
Images
Audio
Video

GPT-5.5 Pro

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.

Gemini 3.8 Flash

Proprietary

Closed source

GPT-5.5 Pro

Proprietary

Closed source

Release Timeline

When each model was launched

Gemini 3.8 Flash was released on 2026-09-02, while GPT-5.5 Pro was released on 2026-04-23.

Gemini 3.8 Flash is 4 months newer than GPT-5.5 Pro.

Gemini 3.8 Flash

Sep 2, 2026

1 weeks ago

4mo newer
GPT-5.5 Pro

Apr 23, 2026

4 months ago

Knowledge Cutoff

When training data ends

Gemini 3.8 Flash has a knowledge cutoff of 2026-03-31, while GPT-5.5 Pro has a cutoff of 2025-12-01.

Gemini 3.8 Flash has more recent training data (up to 2026-03-31), making it potentially better informed about events through that date compared to GPT-5.5 Pro (2025-12-01).

Gemini 3.8 Flash

Mar 2026

3 mo newer
GPT-5.5 Pro

Dec 2025

Provider Availability

Gemini 3.8 Flash is available from Google. GPT-5.5 Pro is available from OpenAI.

Gemini 3.8 Flash

google logo
Google
Input Price:Input: $0.75/1MOutput Price:Output: $3.75/1M

GPT-5.5 Pro

openai logo
OpenAI
Input Price:Input: $30.00/1MOutput Price:Output: $180.00/1M
* Prices shown are per million tokens

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion→

Judge for yourself.

Run your own prompts against Gemini 3.8 Flash and GPT-5.5 Pro side-by-side, then vote on the output you prefer.

Gemini 3.8 Flash
✓ Preferred
GPT-5.5 Pro
Open in Playground

FAQ

Common questions about Gemini 3.8 Flash vs GPT-5.5 Pro.

Which is better, Gemini 3.8 Flash or GPT-5.5 Pro?

Gemini 3.8 Flash and GPT-5.5 Pro are closely matched on the LLM Stats Score at 51.2 and 44.9. Gemini 3.8 Flash is made by Google and GPT-5.5 Pro is made by OpenAI. The best choice depends on your use case — compare their capability indexes, individual benchmarks, pricing, and limits above.

How does Gemini 3.8 Flash compare to GPT-5.5 Pro in benchmarks?

Gemini 3.8 Flash scores Terminal-Bench 2.1: 89.4%, LVBench: 87.1%, CharXiv-R: 86.2%, LABBench2: 86.2%, DeepSWE 1.1: 73.7%. GPT-5.5 Pro scores BrowseComp: 90.1%, GDPval-MM: 82.3%, Humanity's Last Exam: 57.2%, FrontierMath: 39.6%, GeneBench: 33.2%.

Is Gemini 3.8 Flash cheaper than GPT-5.5 Pro?

Gemini 3.8 Flash is 40.0x cheaper for input tokens. Gemini 3.8 Flash costs $0.75/M input and $3.75/M output via google. GPT-5.5 Pro costs $30.00/M input and $180.00/M output via openai.

What are the context window sizes for Gemini 3.8 Flash and GPT-5.5 Pro?

Gemini 3.8 Flash supports 1.0M tokens and GPT-5.5 Pro supports 1.1M tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

What are the main differences between Gemini 3.8 Flash and GPT-5.5 Pro?

Key differences include LLM Stats Score (51.2 vs 44.9), context window (1.0M vs 1.1M), input pricing ($0.75 vs $30.00/M). See the full comparison above for benchmark-by-benchmark results.

Who makes Gemini 3.8 Flash and GPT-5.5 Pro?

Gemini 3.8 Flash is developed by Google and GPT-5.5 Pro is developed by OpenAI.

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