Model comparison
Grok 4 vs Gemini 2.5 Flash
- Input
- $3.00 / 1M tokens
- Output
- $15.00 / 1M tokens
- Context
- 256K
- Released
- 2025-07-09
- Input
- $0.30 / 1M tokens (text / image / video); $1.00 / 1M tokens (audio)
- Output
- $2.50 / 1M tokens (includes thinking tokens)
- Context
- 1M
- Released
- 2025-04-17
Grok 4 scores higher on 4 of the 4 benchmarks both models report; Gemini 2.5 Flash is cheaper on input tokens ($0.3 vs $3 per 1M, 10×); Gemini 2.5 Flash has the larger context window (1M vs 256K).
Specs and pricing side by side
| Spec | Grok 4 | Gemini 2.5 Flash |
|---|---|---|
| Maker | xAI (Grok) | |
| Released | 2025-07-09 | 2025-04-17 |
| Context window | 256K | 1M |
| Max output | 8K | 64K |
| Input price | $3.00 / 1M tokens | $0.30 / 1M tokens (text / image / video); $1.00 / 1M tokens (audio) |
| Output price | $15.00 / 1M tokens | $2.50 / 1M tokens (includes thinking tokens) |
| License | Proprietary | Proprietarysame |
| Weights | API only | API onlysame |
| Modalities | Text, Vision | Text, Vision, Audio, Video, PDF |
| Knowledge cutoff | November 2024 | January 2025 |
Not published by either maker: parameters.
Benchmarks both models report
| Benchmark | Grok 4 | Gemini 2.5 Flash |
|---|---|---|
| Humanity's Last Exam | 41% | 11% |
| GPQA | 87.5% | 82.8% |
| AIME 2025 | 91.7% | 72% |
| LiveCodeBench | 79% | 59.3% |
Scores are as published by each maker or its cited source; harness, reasoning effort and date can differ between rows, so treat small gaps as ties. Sources are listed on each model page.
Which one should you pick?
Pick Grok 4 if…
- You care about Humanity's Last Exam, GPQA, AIME 2025 (it scores higher on 4 shared benchmarks).
- Your use case is: hard STEM and competition-math problem solving (AIME/HMMT/USAMO-style reasoning).
Pick Gemini 2.5 Flash if…
- Cost matters: input tokens cost 10× less ($0.3 vs $3 per 1M).
- You need the longer context (1M vs 256K).
- You need Audio / Video / PDF input, which Grok 4 lacks.
- Your use case is: high-volume chat, summarization, and extraction where cost and latency matter.
FAQ
Which is better, Grok 4 or Gemini 2.5 Flash?
Grok 4 scores higher on 4 of the 4 benchmarks both models report; Gemini 2.5 Flash is cheaper on input tokens ($0.3 vs $3 per 1M, 10×); Gemini 2.5 Flash has the larger context window (1M vs 256K). The better pick depends on whether you value benchmark scores, price per token, context length or openness for your workload.
How much cheaper is Gemini 2.5 Flash?
Grok 4: $3.00 / 1M tokens input, $15.00 / 1M tokens output. Gemini 2.5 Flash: $0.30 / 1M tokens (text / image / video); $1.00 / 1M tokens (audio) input, $2.50 / 1M tokens (includes thinking tokens) output (list API prices as published by each maker).
What are the context windows of Grok 4 and Gemini 2.5 Flash?
Grok 4 offers 256K with up to 8K output; Gemini 2.5 Flash offers 1M with up to 64K output.
Is Grok 4 newer than Gemini 2.5 Flash?
Grok 4 was released 2025-07-09; Gemini 2.5 Flash was released 2025-04-17.