Gemini 2.5 Flash vs GPT-5
Pricing, benchmarks, and use case comparison
Quick take
- •Gemini 2.5 Flash is meaningfully stronger at speed (90 vs 68 on our capability index).
- •GPT-5 is meaningfully stronger at math (92 vs 74).
- •Gemini 2.5 Flash is 76% cheaper on input tokens, which compounds fast on high-volume or agentic workloads.
- •GPT-5 has a 400,000 tokens (128,000 max output) context window vs 1,048,576 tokens (1M) input; up to 65,535 output - better for whole-repo or long-document work.
Specs comparison
| Gemini 2.5 Flash | GPT-5 | |
|---|---|---|
| Provider | Google DeepMind | OpenAI |
| Type | Closed source | Closed source |
| Context window | 1,048,576 tokens (1M) input; up to 65,535 output | ✓400,000 tokens (128,000 max output) |
| Input / 1M tokens | ✓$0.30 | $1.25 |
| Output / 1M tokens | $2.50 | $10.00 |
| Release date | 2025-06 | 2025-08 |
Benchmarks
| Benchmark | Gemini 2.5 Flash | GPT-5 |
|---|---|---|
| Context window | 1M tokens | - |
| Input price | $0.30/1M | - |
| SWE-bench Verified | - | 74.9% |
| AIME 2025 | - | 94.6% |
| GPQA (GPT-5 pro) | - | 88.4% |
Scores sourced from official provider release posts and independent benchmark aggregators.
Which should you choose?
Choose Gemini 2.5 Flash if...
- →High-volume, latency-sensitive production workloads
- →Chatbots, extraction, classification, and summarization at scale
- →You need decent reasoning but must control costs
Choose GPT-5 if...
- →You want strong reasoning at the lowest frontier-model price
- →Existing GPT-5-based systems that are already tuned and validated
- →General coding, math, and reasoning workloads on a budget