Gemini 1.5 Flash vs Gemini 2.5 Pro Comparison

Comparing Gemini 1.5 Flash and Gemini 2.5 Pro across benchmarks, pricing, and capabilities.

Want to compare interactively?Try the playground

Performance Benchmarks

Comparative analysis across standard metrics

5 benchmarks

Gemini 1.5 Flash outperforms in 0 benchmarks, while Gemini 2.5 Pro is better at 5 benchmarks (GPQA, MMMU, MRCR, Vibe-Eval, Video-MME).

Gemini 2.5 Pro significantly outperforms across most benchmarks.

Sat Mar 14 2026 • llm-stats.com

Arena Performance

Human preference votes

Pricing Analysis

Price comparison per million tokens

Gemini 1.5 Flash costs less

For input processing, Gemini 1.5 Flash ($0.15/1M tokens) is 8.3x cheaper than Gemini 2.5 Pro ($1.25/1M tokens).

For output processing, Gemini 1.5 Flash ($0.60/1M tokens) is 16.7x cheaper than Gemini 2.5 Pro ($10.00/1M tokens).

In conclusion, Gemini 2.5 Pro is more expensive than Gemini 1.5 Flash.*

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

Lowest available price from all providers

Sat Mar 14 2026 • llm-stats.com

Gemini 1.5 Flash

Input tokens$0.15

Output tokens$0.60

Best providerGoogle

Gemini 2.5 Pro

Input tokens$1.25

Output tokens$10.00

Best providerGoogle

Notice missing or incorrect data?Start an Issue→

Context Window

Maximum input and output token capacity

Both models have the same input context window of 1,048,576 tokens. Gemini 2.5 Pro can generate longer responses up to 65,536 tokens, while Gemini 1.5 Flash is limited to 8,192 tokens.

Gemini 1.5 Flash

Input1,048,576 tokens

Output8,192 tokens

Gemini 2.5 Pro

Input1,048,576 tokens

Output65,536 tokens

Sat Mar 14 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

Both Gemini 1.5 Flash and Gemini 2.5 Pro support multimodal inputs.

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

Gemini 1.5 Flash

Text

Images

Audio

Video

Gemini 2.5 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 1.5 Flash

Proprietary

Closed source

Gemini 2.5 Pro

Proprietary

Closed source

Release Timeline

When each model was launched

Gemini 1.5 Flash was released on 2024-05-01, while Gemini 2.5 Pro was released on 2025-05-20.

Gemini 2.5 Pro is 13 months newer than Gemini 1.5 Flash.

Gemini 1.5 Flash

May 1, 2024

1.9 years ago

Gemini 2.5 Pro

May 20, 2025

9 months ago

1.1yr newer

Knowledge Cutoff

When training data ends

Gemini 1.5 Flash has a knowledge cutoff of 2023-11-01, while Gemini 2.5 Pro has a cutoff of 2025-01-31.

Gemini 2.5 Pro has more recent training data (up to 2025-01-31), making it potentially better informed about events through that date compared to Gemini 1.5 Flash (2023-11-01).

Gemini 1.5 Flash

Nov 2023

Gemini 2.5 Pro

Jan 2025

1.2 yr newer

Provider Availability

Gemini 1.5 Flash is available from Google. Gemini 2.5 Pro is available from Google. The availability of providers can affect quality of the model and reliability.