# Gemini 3.5 Flash vs Claude Opus 4.8

On provider list prices, Gemini 3.5 Flash costs $1.50 per million input tokens against $5 for Claude Opus 4.8: 3.3x apart. Output is $9 against $25 (2.8x).

## Specifications

| | Gemini 3.5 Flash | Claude Opus 4.8 |
| --- | --- | --- |
| Lab | Google | Anthropic |
| Access | API only | API only |
| Context window | 1M tokens | 200K tokens |
| List price, input | $1.50 / M tokens | $5 / M tokens |
| List price, output | $9 / M tokens | $25 / M tokens |
| Cached input | n/a | n/a |
| License | Proprietary API | Proprietary API |
| Fine-tunable | No | No |

Specifications and provider list prices from the Allocate catalog, checked 2026-07-21.

## What the numbers say

Take 1,000,000 requests a month at 1,200 input and 350 output tokens each. That workload costs $4,950 a month on Gemini 3.5 Flash and $14,750 on Claude Opus 4.8 at list: a gap of $9,800, or 3.0x.

Gemini 3.5 Flash reads 1M tokens per request against 200K for Claude Opus 4.8, 5.0x the window. That decides which one can take whole documents without splitting them.

## Choose Gemini 3.5 Flash for

- High-volume support and triage
- Document extraction at scale
- Vision and OCR pipelines

## Choose Claude Opus 4.8 for

- Hardest reasoning problems
- High-stakes analysis
- Escalation tier for agents

## Common questions

### Which is cheaper, Gemini 3.5 Flash or Claude Opus 4.8?

Gemini 3.5 Flash, on this workload shape. At list prices it is $1.50/$9 per million tokens in and out against $5/$25 for Claude Opus 4.8. Billed on Allocate: $1.60/$9.63 against $5.35/$26.75.

### Which has the bigger context window?

Gemini 3.5 Flash: 1,000,000 tokens (1M) against 200,000 (200K) for Claude Opus 4.8.

### Can I fine-tune Gemini 3.5 Flash or Claude Opus 4.8?

No. Both are closed models served over API. If you want a model you can train and own, start from an open-weights base in the catalog.

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[HTML page](https://allocate.network/compare/gemini-3-5-flash-vs-opus-4-8) · [Gemini 3.5 Flash](https://allocate.network/models/gemini-3-5-flash.md) · [Claude Opus 4.8](https://allocate.network/models/opus-4-8.md) · [Machine-readable catalog](https://allocate.network/catalog.json)