Model Comparison

Gemini 2.5 Flash vs GPT-4.5Which is better in 2026?

Gemini 2.5 Flash significantly outperforms across most benchmarks. Gemini 2.5 Flash is 110.3x cheaper per token.

Verdict: Gemini 2.5 Flash vs GPT-4.5 — which is better?

Gemini 2.5 Flash (by Google) and GPT-4.5 (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.

Gemini 2.5 Flash outperforms in 5 benchmarks (Aider-Polyglot Edit, AIME 2024, GPQA, MMMU, SWE-Bench Verified), while GPT-4.5 is better at 1 benchmark (SimpleQA). Gemini 2.5 Flash significantly outperforms across most benchmarks.

On price, Gemini 2.5 Flash is roughly 110.3x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.

Gemini 2.5 Flash also accepts a larger context window (1,048,576 input tokens), making it the stronger choice for long documents and large codebases.

Choose Gemini 2.5 Flash if…

  • you want the strongest raw capability — it leads on 5 of 6 shared benchmarks
  • cost matters — it's about 110.3x cheaper per token
  • you process long inputs — it offers a 1,048,576 token context window
  • you want the most recent training data — it shipped May 2025

Choose GPT-4.5 if…

  • you want predictable pricing at $75.00/M input and $150.00/M output
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Performance Benchmarks

Comparative analysis across standard metrics

6 benchmarks

Gemini 2.5 Flash outperforms in 5 benchmarks (Aider-Polyglot Edit, AIME 2024, GPQA, MMMU, SWE-Bench Verified), while GPT-4.5 is better at 1 benchmark (SimpleQA).

Gemini 2.5 Flash significantly outperforms across most benchmarks.

Tue Jun 16 2026 • llm-stats.com

Arena Performance

Human preference votes

Pricing Analysis

Price comparison per million tokens

Gemini 2.5 Flash costs less

For input processing, Gemini 2.5 Flash ($0.30/1M tokens) is 250.0x cheaper than GPT-4.5 ($75.00/1M tokens).

For output processing, Gemini 2.5 Flash ($2.50/1M tokens) is 60.0x cheaper than GPT-4.5 ($150.00/1M tokens).

In conclusion, GPT-4.5 is more expensive than Gemini 2.5 Flash.*

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

Lowest available price from all providers
Tue Jun 16 2026 • llm-stats.com
Google
Gemini 2.5 Flash
Input tokens$0.30
Output tokens$2.50
Best providerGoogle
OpenAI
GPT-4.5
Input tokens$75.00
Output tokens$150.00
Best providerOpenAI
Notice missing or incorrect data?Start an Issue→

Context Window

Maximum input and output token capacity

Gemini 2.5 Flash accepts 1,048,576 input tokens compared to GPT-4.5's 128,000 tokens. Gemini 2.5 Flash can generate longer responses up to 65,536 tokens, while GPT-4.5 is limited to 4,096 tokens.

Google
Gemini 2.5 Flash
Input1,048,576 tokens
Output65,536 tokens
OpenAI
GPT-4.5
Input128,000 tokens
Output4,096 tokens
Tue Jun 16 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

Both Gemini 2.5 Flash and GPT-4.5 support multimodal inputs.

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

Gemini 2.5 Flash

Text
Images
Audio
Video

GPT-4.5

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 2.5 Flash

Proprietary

Closed source

GPT-4.5

Proprietary

Closed source

Release Timeline

When each model was launched

Gemini 2.5 Flash was released on 2025-05-20, while GPT-4.5 was released on 2025-02-27.

Gemini 2.5 Flash is 3 months newer than GPT-4.5.

Gemini 2.5 Flash

May 20, 2025

1.1 years ago

2mo newer
GPT-4.5

Feb 27, 2025

1.3 years ago

Knowledge Cutoff

When training data ends

Gemini 2.5 Flash has a documented knowledge cutoff of 2025-01-31, while GPT-4.5's cutoff date is not specified.

We can confirm Gemini 2.5 Flash's training data extends to 2025-01-31, but cannot make a direct comparison without GPT-4.5's cutoff date.

Gemini 2.5 Flash

Jan 2025

GPT-4.5

—

Provider Availability

Gemini 2.5 Flash is available from Google. GPT-4.5 is available from OpenAI.

Gemini 2.5 Flash

google logo
Google
Input Price:Input: $0.30/1MOutput Price:Output: $2.50/1M

GPT-4.5

openai logo
OpenAI
Input Price:Input: $75.00/1MOutput Price:Output: $150.00/1M
* Prices shown are per million tokens

Outputs Comparison

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Key Takeaways

Google
Larger context window (1,048,576 tokens)
Less expensive input tokens
Less expensive output tokens
Higher Aider-Polyglot Edit score (56.7% vs 44.9%)
Higher AIME 2024 score (88.0% vs 36.7%)
Higher GPQA score (82.8% vs 69.5%)
Higher MMMU score (79.7% vs 75.2%)
Higher SWE-Bench Verified score (60.4% vs 38.0%)
OpenAI
Higher SimpleQA score (62.5% vs 26.9%)
GoogleGemini 2.5 Flash
OpenAIGPT-4.5
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Detailed Comparison

AI Model Comparison Table
Feature
Google
Gemini 2.5 Flash
OpenAI
GPT-4.5

FAQ

Common questions about Gemini 2.5 Flash vs GPT-4.5.

Which is better, Gemini 2.5 Flash or GPT-4.5?

Gemini 2.5 Flash significantly outperforms across most benchmarks. Gemini 2.5 Flash is made by Google and GPT-4.5 is made by OpenAI. The best choice depends on your use case — compare their benchmark scores, pricing, and capabilities above.

How does Gemini 2.5 Flash compare to GPT-4.5 in benchmarks?

Gemini 2.5 Flash scores Global-MMLU-Lite: 88.4%, AIME 2024: 88.0%, FACTS Grounding: 85.3%, GPQA: 82.8%, MMMU: 79.7%. GPT-4.5 scores GSM8k: 97.0%, MMLU: 90.8%, CharXiv-D: 90.0%, IFEval: 88.2%, HumanEval: 88.0%.

Is Gemini 2.5 Flash cheaper than GPT-4.5?

Gemini 2.5 Flash is 250.0x cheaper for input tokens. Gemini 2.5 Flash costs $0.30/M input and $2.50/M output via google. GPT-4.5 costs $75.00/M input and $150.00/M output via openai.

What are the context window sizes for Gemini 2.5 Flash and GPT-4.5?

Gemini 2.5 Flash supports 1.0M tokens and GPT-4.5 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 2.5 Flash and GPT-4.5?

Key differences include context window (1.0M vs 128K), input pricing ($0.30 vs $75.00/M). See the full comparison above for benchmark-by-benchmark results.

Who makes Gemini 2.5 Flash and GPT-4.5?

Gemini 2.5 Flash is developed by Google and GPT-4.5 is developed by OpenAI.

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