Model Comparison

Gemini 3.1 Pro vs GPT-5.3 ChatWhich is better in 2026?

Comparing Gemini 3.1 Pro and GPT-5.3 Chat across benchmarks, pricing, and capabilities.

Verdict: Gemini 3.1 Pro vs GPT-5.3 Chat — which is better?

Gemini 3.1 Pro (by Google) and GPT-5.3 Chat (by OpenAI) are two of the AI models people compare most. Here is how they stack up on benchmarks, price and capabilities, and which one to pick in 2026.

On price, GPT-5.3 Chat is roughly 1.2x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.

Gemini 3.1 Pro also accepts a larger context window (1,048,576 input tokens), making it the stronger choice for long documents and large codebases.

Choose Gemini 3.1 Pro if…

  • you process long inputs — it offers a 1,048,576 token context window

Choose GPT-5.3 Chat if…

  • cost matters — it's about 1.2x cheaper per token
  • you want the most recent training data — it shipped Mar 2026

Performance Benchmarks

Comparative analysis across standard metrics

No common benchmarks found

Gemini 3.1 Pro and GPT-5.3 Chatdon't have any common benchmark datasets to compare. They may have been evaluated on different testing suites.

Arena Performance

Human preference votes

Pricing Analysis

Price comparison per million tokens

GPT-5.3 Chat costs less

For input processing, Gemini 3.1 Pro ($2.50/1M tokens) is 1.4x more expensive than GPT-5.3 Chat ($1.75/1M tokens).

For output processing, Gemini 3.1 Pro ($15.00/1M tokens) is 1.1x more expensive than GPT-5.3 Chat ($14.00/1M tokens).

In conclusion, Gemini 3.1 Pro is more expensive than GPT-5.3 Chat.*

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

Lowest available price from all providers
Mon Jul 27 2026 • llm-stats.com
Google
Gemini 3.1 Pro
Input tokens$2.50
Output tokens$15.00
Best providerGoogle
OpenAI
GPT-5.3 Chat
Input tokens$1.75
Output tokens$14.00
Best providerOpenAI
Notice missing or incorrect data?Start an Issue→

Context Window

Maximum input and output token capacity

Gemini 3.1 Pro accepts 1,048,576 input tokens compared to GPT-5.3 Chat's 128,000 tokens. Gemini 3.1 Pro can generate longer responses up to 65,536 tokens, while GPT-5.3 Chat is limited to 16,384 tokens.

Google
Gemini 3.1 Pro
Input1,048,576 tokens
Output65,536 tokens
OpenAI
GPT-5.3 Chat
Input128,000 tokens
Output16,384 tokens
Mon Jul 27 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

Both Gemini 3.1 Pro and GPT-5.3 Chat support multimodal inputs.

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

Gemini 3.1 Pro

Text
Images
Audio
Video

GPT-5.3 Chat

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 3.1 Pro

Proprietary

Closed source

GPT-5.3 Chat

Proprietary

Closed source

Release Timeline

When each model was launched

Gemini 3.1 Pro was released on 2026-02-19, while GPT-5.3 Chat was released on 2026-03-04.

GPT-5.3 Chat is 0 month newer than Gemini 3.1 Pro.

Gemini 3.1 Pro

Feb 19, 2026

5 months ago

GPT-5.3 Chat

Mar 4, 2026

4 months ago

1w newer

Knowledge Cutoff

When training data ends

Gemini 3.1 Pro has a knowledge cutoff of 2025-01-31, while GPT-5.3 Chat has a cutoff of 2025-08-31.

GPT-5.3 Chat has more recent training data (up to 2025-08-31), making it potentially better informed about events through that date compared to Gemini 3.1 Pro (2025-01-31).

Gemini 3.1 Pro

Jan 2025

GPT-5.3 Chat

Aug 2025

7 mo newer

Provider Availability

Gemini 3.1 Pro is available from Google. GPT-5.3 Chat is available from OpenAI.

Gemini 3.1 Pro

google logo
Google
Input Price:Input: $2.50/1MOutput Price:Output: $15.00/1M

GPT-5.3 Chat

openai logo
OpenAI
Input Price:Input: $1.75/1MOutput Price:Output: $14.00/1M
* Prices shown are per million tokens

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion→

Key Takeaways

Google
Larger context window (1,048,576 tokens)
OpenAI
Less expensive input tokens
Less expensive output tokens

Detailed Comparison

Interactive Arena

Judge for yourself.

Run your own prompts against Gemini 3.1 Pro and GPT-5.3 Chat side-by-side, then vote on the output you prefer.

Gemini 3.1 Pro
✓ Preferred
GPT-5.3 Chat
Open in Playground
AI Model Comparison Table
Feature
Google
Gemini 3.1 Pro
OpenAI
GPT-5.3 Chat

FAQ

Common questions about Gemini 3.1 Pro vs GPT-5.3 Chat.

Which is better, Gemini 3.1 Pro or GPT-5.3 Chat?

Gemini 3.1 Pro (Google) and GPT-5.3 Chat (OpenAI) each have strengths in different areas. Compare their benchmark scores, pricing, context windows, and capabilities above to determine which fits your needs.

How does Gemini 3.1 Pro compare to GPT-5.3 Chat in benchmarks?

Gemini 3.1 Pro scores t2-bench: 99.3%, LiveCodeBench Pro: 96.2%, GPQA: 94.3%, MMMLU: 92.6%, BrowseComp: 85.9%. GPT-5.3 Chat scores HealthBench: 54.1%, HealthBench Hard: 25.9%.

Is Gemini 3.1 Pro cheaper than GPT-5.3 Chat?

GPT-5.3 Chat is 1.4x cheaper for input tokens. Gemini 3.1 Pro costs $2.50/M input and $15.00/M output via google. GPT-5.3 Chat costs $1.75/M input and $14.00/M output via openai.

What are the context window sizes for Gemini 3.1 Pro and GPT-5.3 Chat?

Gemini 3.1 Pro supports 1.0M tokens and GPT-5.3 Chat supports 128K tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

What are the main differences between Gemini 3.1 Pro and GPT-5.3 Chat?

Key differences include context window (1.0M vs 128K), input pricing ($2.50 vs $1.75/M). See the full comparison above for benchmark-by-benchmark results.

Who makes Gemini 3.1 Pro and GPT-5.3 Chat?

Gemini 3.1 Pro is developed by Google and GPT-5.3 Chat is developed by OpenAI.

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