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Gemini 3 Pro vs GPT-5.3 Codex

Gemini 3 Pro and GPT-5.3 Codex are closely matched at 38.6 and 36.5 on the LLM Stats Score. Gemini 3 Pro is 1.1x cheaper per token.

Google · OpenAI · Updated for 2026

Which is better?

Gemini 3 Pro and GPT-5.3 Codex are closely matched on the overall LLM Stats Score at 38.6 and 36.5.

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

On price, Gemini 3 Pro is roughly 1.1x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.

Gemini 3 Pro also accepts a larger context window (1,048,576 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 Pro

  • cost matters — it's about 1.1x cheaper per token
  • you process long inputs — it offers a 1,048,576 token context window

Choose GPT-5.3 Codex

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

At a glance

The differences that matter most.

Gemini 3 Pro
Google
GPT-5.3 Codex
OpenAI
Core performance indexes
LLM Stats Score
38.6
#64
36.5
#75
Reasoning
38.6
#61
37.2
#69
Coding
24.5
#72
29.9
#53
Agents
15.3
#85
22.8
#57
Cost, coverage & limits
Benchmark wins
1 of 2
1 of 2
Input price
$2.00 / M
$1.75 / M
Output price
$12.00 / M
$14.00 / M
Context window
1,048,576
400,000

Individual benchmarks

21 reported for Gemini 3 Pro · 6 for GPT-5.3 Codex

2 shared

Gemini 3 Pro outperforms in 1 benchmarks (LiveBench), while GPT-5.3 Codex is better at 1 benchmark (Terminal-Bench 2.0).

Both models are evenly matched across the benchmarks.

Sun Sep 20 2026 • llm-stats.com

Human preference

Blind head-to-head votes and playground preference scores

Pricing Analysis

Price comparison per million tokens

Gemini 3 Pro costs less

For input processing, Gemini 3 Pro ($2.00/1M tokens) is 1.1x more expensive than GPT-5.3 Codex ($1.75/1M tokens).

For output processing, Gemini 3 Pro ($12.00/1M tokens) is 1.2x cheaper than GPT-5.3 Codex ($14.00/1M tokens).

In conclusion, GPT-5.3 Codex is more expensive than Gemini 3 Pro.*

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

Lowest available price from all providers
Sun Sep 20 2026 • llm-stats.com
Google
Gemini 3 Pro
Input tokens$2.00
Output tokens$12.00
Best providerGoogle
OpenAI
GPT-5.3 Codex
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 Pro accepts 1,048,576 input tokens compared to GPT-5.3 Codex's 400,000 tokens. GPT-5.3 Codex can generate longer responses up to 128,000 tokens, while Gemini 3 Pro is limited to 65,536 tokens.

Google
Gemini 3 Pro
Input1,048,576 tokens
Output65,536 tokens
OpenAI
GPT-5.3 Codex
Input400,000 tokens
Output128,000 tokens
Sun Sep 20 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

Both Gemini 3 Pro and GPT-5.3 Codex support multimodal inputs.

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

Gemini 3 Pro

Text
Images
Audio
Video

GPT-5.3 Codex

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 Pro

Proprietary

Closed source

GPT-5.3 Codex

Proprietary

Closed source

Release Timeline

When each model was launched

Gemini 3 Pro was released on 2025-11-18, while GPT-5.3 Codex was released on 2026-02-05.

GPT-5.3 Codex is 3 months newer than Gemini 3 Pro.

Gemini 3 Pro

Nov 18, 2025

10 months ago

GPT-5.3 Codex

Feb 5, 2026

7 months ago

2mo newer

Knowledge Cutoff

When training data ends

Gemini 3 Pro has a documented knowledge cutoff of 2025-01-31, while GPT-5.3 Codex's cutoff date is not specified.

We can confirm Gemini 3 Pro's training data extends to 2025-01-31, but cannot make a direct comparison without GPT-5.3 Codex's cutoff date.

Gemini 3 Pro

Jan 2025

GPT-5.3 Codex

—

Provider Availability

Gemini 3 Pro is available from Google. GPT-5.3 Codex is available from OpenAI.

Gemini 3 Pro

google logo
Google
Input Price:Input: $2.00/1MOutput Price:Output: $12.00/1M

GPT-5.3 Codex

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→

Judge for yourself.

Run your own prompts against Gemini 3 Pro and GPT-5.3 Codex side-by-side, then vote on the output you prefer.

Gemini 3 Pro
✓ Preferred
GPT-5.3 Codex
Open in Playground

FAQ

Common questions about Gemini 3 Pro vs GPT-5.3 Codex.

Which is better, Gemini 3 Pro or GPT-5.3 Codex?

Gemini 3 Pro and GPT-5.3 Codex are closely matched on the LLM Stats Score at 38.6 and 36.5. Gemini 3 Pro is made by Google and GPT-5.3 Codex 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 Pro compare to GPT-5.3 Codex in benchmarks?

Gemini 3 Pro scores AIME 2025: 100.0%, Vending-Bench 2: 100.0%, Global PIQA: 93.4%, GPQA: 91.9%, MMMLU: 91.8%. GPT-5.3 Codex scores SWE-Lancer (IC-Diamond subset): 81.4%, Cybersecurity CTFs: 77.6%, Terminal-Bench 2.0: 77.3%, LiveBench: 72.8%, OSWorld-Verified: 64.7%.

Is Gemini 3 Pro cheaper than GPT-5.3 Codex?

GPT-5.3 Codex is 1.1x cheaper for input tokens. Gemini 3 Pro costs $2.00/M input and $12.00/M output via google. GPT-5.3 Codex costs $1.75/M input and $14.00/M output via openai.

What are the context window sizes for Gemini 3 Pro and GPT-5.3 Codex?

Gemini 3 Pro supports 1.0M tokens and GPT-5.3 Codex supports 400K 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 Pro and GPT-5.3 Codex?

Key differences include LLM Stats Score (38.6 vs 36.5), context window (1.0M vs 400K), input pricing ($2.00 vs $1.75/M). See the full comparison above for benchmark-by-benchmark results.

Who makes Gemini 3 Pro and GPT-5.3 Codex?

Gemini 3 Pro is developed by Google and GPT-5.3 Codex is developed by OpenAI.

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