Gemini 3.5 Flash vs GPT-5
Benchmarks, API pricing and specs, head to head. Data updated 2026-06-10.
Gemini 3.5 Flash
Google · May 2026
Google's I/O 2026 headliner: near-Pro intelligence at Flash speed, 78.8% on SWE-bench Verified with full multimodal input.
GPT-5
70.7OpenAI · Aug 2025
OpenAI's August 2025 unified flagship that merged the GPT and o-series reasoning lines into one model with selectable effort.
The verdict
Gemini 3.5 Flash wins 1 of the 1 benchmarks these models share, against 0 for GPT-5. Gemini 3.5 Flash is about 1.0x cheaper per blended million tokens (3:1 input:output mix). Gemini 3.5 Flash also takes 1M of context versus 400K for GPT-5.
Benchmark head-to-head 1–0
Specs & pricing
| Gemini 3.5 Flash | GPT-5 | |
|---|---|---|
| modhub Index | — | 70.7 |
| Input price / 1M | $1.5 | $1.25 |
| Output price / 1M | $9 | $10 |
| Context window | 1M | 400K |
| Max output | 66K | 128K |
| Open weights | no | no |
| Reasoning model | yes | yes |
| Multimodal input | text, image, audio, video | text, image |
| Knowledge cutoff | Feb 2026 | Sep 2024 |
| Released | May 2026 | Aug 2025 |
| Example monthly cost* | $28.50 | $27.50 |
* 10M input + 1.5M output tokens per month at list prices, no caching. Green = better value on that row.
Frequently asked questions
- Which is better, Gemini 3.5 Flash or GPT-5?
- Gemini 3.5 Flash wins 1 of the 1 benchmarks these models share, against 0 for GPT-5. Gemini 3.5 Flash is about 1.0x cheaper per blended million tokens (3:1 input:output mix). Gemini 3.5 Flash also takes 1M of context versus 400K for GPT-5.
- Which is cheaper, Gemini 3.5 Flash or GPT-5?
- Gemini 3.5 Flash costs $1.5/$9 per million input/output tokens, while GPT-5 costs $1.25/$10. For a typical workload of 10M input and 1.5M output tokens per month, that's $28.50 versus $27.50.
- Which model is better for coding, Gemini 3.5 Flash or GPT-5?
- On SWE-bench Verified — the standard agentic-coding benchmark — Gemini 3.5 Flash scores 78.8% versus 74.9% for GPT-5, making Gemini 3.5 Flash the stronger pick for coding agents.