# Anthropic vs OpenAI

Canonical: https://inetgeek.com/compare/anthropic-vs-openai/

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

## At a glance

| Criterion | Anthropic | OpenAI |
| --- | --- | --- |
| 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 a second rate above the short-context threshold — long-context input and output cost roughly double. Batch, Flex, Fast and standard tiers are priced separately, and regional processing adds a 10% uplift on models released from March 2026. |
| 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. | $10 per million input tokens for gpt-6-astra at short context, rising to $20 above the short-context threshold. gpt-5.6-sol is $4 and gpt-5.6-terra $2. |
| 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. | $50 per million output tokens for gpt-6-astra at short context, $75 at long context. |
| Input price, cheapest model | $1 per million input tokens for Claude Haiku 4.5, the cheapest current model, with output at $5. | $0.20 per million input tokens for gpt-5.6-luna at short context, with output at $1.20. |
| 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. | 1,050,000 tokens on gpt-6-astra, of which at most 922,000 may be input. |
| 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. | 128,000 tokens on gpt-6-astra. |
| Prompt caching | Supported | Supported |
| Batch discount | 50% off both input and output tokens through the Batch API, for asynchronous processing. | 50% off input and output through the Batch API: gpt-6-astra falls from $10/$50 to $5/$25 at short context. |

## 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))
- OpenAI: Per million tokens, with a second rate above the short-context threshold — long-context input and output cost roughly double. Batch, Flex, Fast and standard tiers are priced separately, and regional processing adds a 10% uplift on models released from March 2026. ([source](https://platform.openai.com/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))
- OpenAI: $10 per million input tokens for gpt-6-astra at short context, rising to $20 above the short-context threshold. gpt-5.6-sol is $4 and gpt-5.6-terra $2. ([source](https://platform.openai.com/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))
- OpenAI: $50 per million output tokens for gpt-6-astra at short context, $75 at long context. ([source](https://platform.openai.com/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))
- OpenAI: $0.20 per million input tokens for gpt-5.6-luna at short context, with output at $1.20. ([source](https://platform.openai.com/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))
- OpenAI: 1,050,000 tokens on gpt-6-astra, of which at most 922,000 may be input. ([source](https://platform.openai.com/docs/models/gpt-6-astra))

### 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))
- OpenAI: 128,000 tokens on gpt-6-astra. ([source](https://platform.openai.com/docs/models/gpt-6-astra))

### 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))
- OpenAI: 50% off input and output through the Batch API: gpt-6-astra falls from $10/$50 to $5/$25 at short context. ([source](https://platform.openai.com/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 OpenAI if Work that fits inside the short-context rate, where the cheapest tier is $0.20 per million input tokens and the batch tier halves everything above it.

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: OpenAI — Long prompts cross into the long-context rate and roughly double the bill, which is a cliff the flat-rate vendors do not have.

## Questions this comparison answers

**Should I choose Anthropic or OpenAI?**

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 OpenAI if Work that fits inside the short-context rate, where the cheapest tier is $0.20 per million input tokens and the batch tier halves everything above it.