# Anthropic vs Google Gemini API

Canonical: https://inetgeek.com/compare/anthropic-vs-google-gemini/

Every value below is read from Anthropic's and Google Gemini API's own documentation. See https://inetgeek.com/methodology/ for how.

## At a glance

| Criterion | Anthropic | Google Gemini API |
| --- | --- | --- |
| Pricing model | Per million tokens, priced separately for input and output and per model, with multipliers stacked on top: prompt caching, a 50% batch discount, a 1.1x uplift for US-only inference on Claude 4.6 and later, and a fast-mode premium. | Per million tokens, with dated price changes published in advance — the current Gemini 3.x rates are explicitly promotional through 31 December 2026 and roughly double on 1 January 2027. A free tier exists, and its content is used to improve Google's products where the paid tier's is not. |
| Input price, top model | $10 per million input tokens for Claude Fable 5.1, the most capable model. Claude Opus 5 is $5 and Claude Sonnet 5 is $2. | $0.75 per million input tokens for Gemini 3.8 Flash through 31 December 2026, then $1.50. Gemini 3.1 Pro, still preview, is $2.00 for prompts up to 200k tokens and $4.00 above. |
| Output price, top model | $50 per million output tokens for Claude Fable 5.1. Claude Opus 5 is $25 and Claude Sonnet 5 is $10. | $3.75 per million output tokens for Gemini 3.8 Flash through 31 December 2026, then $7.50. Thinking tokens are billed as output. |
| Input price, cheapest model | $1 per million input tokens for Claude Haiku 4.5, the cheapest current model, with output at $5. | $0.30 per million input tokens for Gemini 3.5 Flash-Lite, with output at $2.50. |
| Context window | 1M tokens on Claude Fable 5.1, Claude Opus 5 and Claude Sonnet 5; 200K on Claude Haiku 4.5. Anthropic states the full 1M window is billed at standard per-token rates. | 1,048,576 tokens for Gemini 3.8 Flash. Read from the Vertex AI model card: the Gemini API docs build their model cards client-side and publish no figure a fetch can read. |
| Max output tokens | 128K tokens on the top three models, 64K on Claude Haiku 4.5. The Batch API supports up to 300K output tokens on several models behind a beta header. | 65,536 tokens for Gemini 3.8 Flash, and Google counts thinking tokens as output. |
| Prompt caching | Supported | Supported |
| Batch discount | 50% off both input and output tokens through the Batch API, for asynchronous processing. | 50% off through the Batch API, which is a paid-tier feature. |

## Where they differ

### Pricing model

- Anthropic: Per million tokens, priced separately for input and output and per model, with multipliers stacked on top: prompt caching, a 50% batch discount, a 1.1x uplift for US-only inference on Claude 4.6 and later, and a fast-mode premium. ([source](https://docs.claude.com/en/docs/about-claude/pricing))
- Google Gemini API: Per million tokens, with dated price changes published in advance — the current Gemini 3.x rates are explicitly promotional through 31 December 2026 and roughly double on 1 January 2027. A free tier exists, and its content is used to improve Google's products where the paid tier's is not. ([source](https://ai.google.dev/gemini-api/docs/pricing))

### Input price, top model

- Anthropic: $10 per million input tokens for Claude Fable 5.1, the most capable model. Claude Opus 5 is $5 and Claude Sonnet 5 is $2. ([source](https://docs.claude.com/en/docs/about-claude/pricing))
- Google Gemini API: $0.75 per million input tokens for Gemini 3.8 Flash through 31 December 2026, then $1.50. Gemini 3.1 Pro, still preview, is $2.00 for prompts up to 200k tokens and $4.00 above. ([source](https://ai.google.dev/gemini-api/docs/pricing))

### Output price, top model

- Anthropic: $50 per million output tokens for Claude Fable 5.1. Claude Opus 5 is $25 and Claude Sonnet 5 is $10. ([source](https://docs.claude.com/en/docs/about-claude/pricing))
- Google Gemini API: $3.75 per million output tokens for Gemini 3.8 Flash through 31 December 2026, then $7.50. Thinking tokens are billed as output. ([source](https://ai.google.dev/gemini-api/docs/pricing))

### Input price, cheapest model

- Anthropic: $1 per million input tokens for Claude Haiku 4.5, the cheapest current model, with output at $5. ([source](https://docs.claude.com/en/docs/about-claude/pricing))
- Google Gemini API: $0.30 per million input tokens for Gemini 3.5 Flash-Lite, with output at $2.50. ([source](https://ai.google.dev/gemini-api/docs/pricing))

### Context window

- Anthropic: 1M tokens on Claude Fable 5.1, Claude Opus 5 and Claude Sonnet 5; 200K on Claude Haiku 4.5. Anthropic states the full 1M window is billed at standard per-token rates. ([source](https://docs.claude.com/en/docs/about-claude/models/overview))
- Google Gemini API: 1,048,576 tokens for Gemini 3.8 Flash. Read from the Vertex AI model card: the Gemini API docs build their model cards client-side and publish no figure a fetch can read. ([source](https://cloud.google.com/vertex-ai/generative-ai/docs/models/gemini/3-8-flash))

### Max output tokens

- Anthropic: 128K tokens on the top three models, 64K on Claude Haiku 4.5. The Batch API supports up to 300K output tokens on several models behind a beta header. ([source](https://docs.claude.com/en/docs/about-claude/models/overview))
- Google Gemini API: 65,536 tokens for Gemini 3.8 Flash, and Google counts thinking tokens as output. ([source](https://cloud.google.com/vertex-ai/generative-ai/docs/models/gemini/3-8-flash))

### Batch discount

- Anthropic: 50% off both input and output tokens through the Batch API, for asynchronous processing. ([source](https://docs.claude.com/en/docs/about-claude/pricing))
- Google Gemini API: 50% off through the Batch API, which is a paid-tier feature. ([source](https://ai.google.dev/gemini-api/docs/pricing))

## Which should you choose?

Pick Anthropic if Teams that want the full 1M-token window at the standard per-token rate rather than a long-context surcharge, and that can use caching and batch to cut a frontier-model bill roughly in half.

Pick Google Gemini API if Getting to a working prototype without a card, then staying on the cheapest frontier-adjacent rates in this set — $0.75 per million input tokens is well under half what Anthropic and OpenAI charge for their top models.

Consider something else: Anthropic — Its cheapest model is $1 per million input tokens, several times what the budget tiers at Google, OpenAI and DeepSeek charge, so high-volume simple work is priced against you.

Consider something else: Google Gemini API — The rates are dated: they roughly double on 1 January 2027, free-tier content is used to improve Google's products, and rate limits are not published anywhere you can read before signing up.

## Documented by only one

- Free tier: Google Gemini API: Yes
- Rate limits: Google Gemini API: Tied to a usage tier — Free, then Tier 1/2/3 unlocked by cumulative spend — and enforced as requests per minute, input tokens per minute and requests per day. Google publishes no numbers in the docs: limits are viewed in AI Studio and are stated not to be guaranteed.

## Questions this comparison answers

**Should I choose Anthropic or Google Gemini API?**

Pick Anthropic if Teams that want the full 1M-token window at the standard per-token rate rather than a long-context surcharge, and that can use caching and batch to cut a frontier-model bill roughly in half.
Pick Google Gemini API if Getting to a working prototype without a card, then staying on the cheapest frontier-adjacent rates in this set — $0.75 per million input tokens is well under half what Anthropic and OpenAI charge for their top models.