Model Comparison

GPT-5 High vs Gemini 2.5 Flash

GPT-5 High significantly outperforms across most benchmarks. Gemini 2.5 Flash is 4.0x cheaper per token.

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Performance Benchmarks

Comparative analysis across standard metrics

2 benchmarks

GPT-5 High outperforms in 2 benchmarks (AIME 2025, GPQA), while Gemini 2.5 Flash is better at 0 benchmarks.

GPT-5 High significantly outperforms across most benchmarks.

Thu Apr 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, GPT-5 High ($1.25/1M tokens) is 4.2x more expensive than Gemini 2.5 Flash ($0.30/1M tokens).

For output processing, GPT-5 High ($10.00/1M tokens) is 4.0x more expensive than Gemini 2.5 Flash ($2.50/1M tokens).

In conclusion, GPT-5 High is more expensive than Gemini 2.5 Flash.*

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

Lowest available price from all providers
Thu Apr 16 2026 • llm-stats.com
OpenAI
GPT-5 High
Input tokens$1.25
Output tokens$10.00
Best providerOpenAI
Google
Gemini 2.5 Flash
Input tokens$0.30
Output tokens$2.50
Best providerGoogle
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Context Window

Maximum input and output token capacity

Gemini 2.5 Flash accepts 1,048,576 input tokens compared to GPT-5 High's 400,000 tokens. GPT-5 High can generate longer responses up to 128,000 tokens, while Gemini 2.5 Flash is limited to 65,536 tokens.

OpenAI
GPT-5 High
Input400,000 tokens
Output128,000 tokens
Google
Gemini 2.5 Flash
Input1,048,576 tokens
Output65,536 tokens
Thu Apr 16 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

Both GPT-5 High and Gemini 2.5 Flash support multimodal inputs.

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

GPT-5 High

Text
Images
Audio
Video

Gemini 2.5 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 High

Proprietary

Closed source

Gemini 2.5 Flash

Proprietary

Closed source

Release Timeline

When each model was launched

GPT-5 High was released on 2025-08-07, while Gemini 2.5 Flash was released on 2025-05-20.

GPT-5 High is 3 months newer than Gemini 2.5 Flash.

GPT-5 High

Aug 7, 2025

8 months ago

2mo newer
Gemini 2.5 Flash

May 20, 2025

11 months ago

Knowledge Cutoff

When training data ends

GPT-5 High has a knowledge cutoff of 2024-09-30, while Gemini 2.5 Flash has a cutoff of 2025-01-31.

Gemini 2.5 Flash has more recent training data (up to 2025-01-31), making it potentially better informed about events through that date compared to GPT-5 High (2024-09-30).

GPT-5 High

Sep 2024

Gemini 2.5 Flash

Jan 2025

4 mo newer

Provider Availability

GPT-5 High is available from OpenAI. Gemini 2.5 Flash is available from Google.

GPT-5 High

openai logo
OpenAI
Input Price:Input: $1.25/1MOutput Price:Output: $10.00/1M

Gemini 2.5 Flash

google logo
Google
Input Price:Input: $0.30/1MOutput Price:Output: $2.50/1M
* Prices shown are per million tokens

Outputs Comparison

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Key Takeaways

OpenAI
Higher AIME 2025 score (94.6% vs 72.0%)
Higher GPQA score (87.3% vs 82.8%)
Google
Larger context window (1,048,576 tokens)
Less expensive input tokens
Less expensive output tokens
OpenAIGPT-5 High
GoogleGemini 2.5 Flash
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Detailed Comparison

AI Model Comparison Table
Feature
OpenAI
GPT-5 High
Google
Gemini 2.5 Flash

FAQ

Common questions about GPT-5 High vs Gemini 2.5 Flash

GPT-5 High significantly outperforms across most benchmarks. GPT-5 High is made by OpenAI and Gemini 2.5 Flash is made by Google. The best choice depends on your use case — compare their benchmark scores, pricing, and capabilities above.
GPT-5 High scores AIME 2025: 94.6%, GPQA: 87.3%. Gemini 2.5 Flash scores Global-MMLU-Lite: 88.4%, AIME 2024: 88.0%, FACTS Grounding: 85.3%, GPQA: 82.8%, MMMU: 79.7%.
Gemini 2.5 Flash is 4.2x cheaper for input tokens. GPT-5 High costs $1.25/M input and $10.00/M output via openai. Gemini 2.5 Flash costs $0.30/M input and $2.50/M output via google.
GPT-5 High supports 400K tokens and Gemini 2.5 Flash supports 1.0M tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.
Key differences include context window (400K vs 1.0M), input pricing ($1.25 vs $0.30/M). See the full comparison above for benchmark-by-benchmark results.
GPT-5 High is developed by OpenAI and Gemini 2.5 Flash is developed by Google.