Comprehensive side-by-side LLM comparison
Both models show comparable benchmark performance. Gemini 2.5 Flash offers 708.2K more tokens in context window than o4 mini. Gemini 2.5 Flash is $4.75 cheaper per million tokens. Both models have their strengths depending on your specific coding needs.
Google DeepMind
Gemini 2.5 Flash, released by Google in June 2025, is a large language model from the Gemini 2.5 family optimized for high-throughput, cost-efficient deployments with multimodal reasoning. It features a 1M token context window, hybrid thinking control, and native support for text, image, video, and audio input. Gemini 2.5 Flash targets latency-sensitive applications, document analysis, and high-volume API workloads that benefit from combined reasoning and generation in a single model.
OpenAI
OpenAI o4 mini, released by OpenAI in April 2025, is a compact reasoning model from the o4 family that combines multimodal understanding with efficient chain-of-thought processing. It features a 200K token context window and native image understanding, with strong performance on mathematics and coding benchmarks relative to its inference cost. o4 mini targets cost-sensitive applications requiring both visual reasoning and mathematical accuracy.
2 months newer

o4 mini
OpenAI
2025-04-16

Gemini 2.5 Flash
Google DeepMind
2025-06-17
Cost per million tokens (USD)
Gemini 2.5 Flash
o4 mini
Context window and performance specifications
Average performance across 3 common benchmarks
Gemini 2.5 Flash
o4 mini
Performance comparison across key benchmark categories
Gemini 2.5 Flash
o4 mini
Available providers and their performance metrics
Gemini 2.5 Flash
Google Cloud Vertex AI
o4 mini
Gemini 2.5 Flash
o4 mini
Gemini 2.5 Flash
o4 mini
OpenAI