Anthropic Claude vs OpenAI API
Anthropic Claude is accessed through four model tiers, Fable 5.1, Opus 5.5, Sonnet 5 and Haiku 4.5, three of which support up to 1 million tokens of context. The OpenAI API centers on the GPT-6 family, split into Astra, Sol and Luna tiers, with shorter context windows at the standard price and a specialized Codex model for coding. Choose Claude for the longest context windows and a coding agent (Claude Code) built into its consumer plans; choose the OpenAI API for the lowest entry price on its fastest tier and for Codex-specific coding pricing.
Facts checked on against the official sources listed at the end. Usage numbers update daily.
Best for
Work needing up to 1 million tokens of context, or Claude Code for agentic coding
Free plan. Paid from $20 a month for Claude Pro; API from $1 input per million tokens on Haiku 4.5.
Best for
Cost-sensitive, high-volume workloads on the cheapest GPT-6 tier, or Codex-specific coding
No free plan. Paid from $0.10 input / $0.50 output per million tokens on GPT-6 Luna.
Anthropic Claude vs OpenAI API at a glance
| Compared on | Anthropic Claude | OpenAI API |
|---|---|---|
| Current flagship family | Fable 5.1, Opus 5.5, Sonnet 5 and Haiku 4.5 | GPT-6, in Astra, Sol and Luna tiers, alongside the earlier GPT-5.6 line |
| Cheapest tier price | Haiku 4.5: $1 input / $5 output per million tokens | GPT-6 Luna: about $0.10 input / $0.50 output per million tokens for short-context calls |
| Top tier price | Fable 5.1: $10 input / $50 output per million tokens | GPT-6 Astra: $10.00 input / $50.00 output per million tokens for short-context calls |
| Maximum context window | 1 million tokens on Fable 5.1, Opus 5.5 and Sonnet 5; 200,000 on Haiku 4.5 | Standard pricing covers short-context calls; long-context variants of GPT-6 are priced higher |
| Dedicated coding model | Claude Code, a coding agent included with Pro and Max consumer plans | gpt-5.3-codex, a specialized model priced at $1.75 input / $14.00 output per million tokens |
| Cost-reduction options | Not a named discount program in the standard API pricing | Batch API at about half the standard rate; cached input tokens discounted about 90% |
| Cloud availability | Amazon Bedrock and Google Cloud Vertex AI | Microsoft Azure OpenAI Service |
| Open source | No, Proprietary | No, Proprietary |
| Free plan | Yes, in the Claude apps; the API has no free tier and is billed per token | No, the API has no free tier and is billed per token from the first request |
| Paid plans from | $20 a month for Claude Pro; API from $1 input per million tokens on Haiku 4.5 | $0.10 input / $0.50 output per million tokens on GPT-6 Luna |
| Made by | Anthropic PBC | OpenAI |
| Launched | 2021 | Not listed |
What's the difference between Anthropic Claude and OpenAI API?
Claude's three largest models support a 1 million token context window, GPT-6's standard pricing covers shorter contexts
Fable 5.1, Opus 5.5 and Sonnet 5 all support up to 1 million tokens of context at their standard price. OpenAI's published GPT-6 Astra, Sol and Luna prices are for short-context calls, with long-context variants priced higher separately.
OpenAI's cheapest tier undercuts Claude's cheapest tier on price
GPT-6 Luna starts around $0.10 input / $0.50 output per million tokens for short-context calls. Claude's cheapest model, Haiku 4.5, costs $1 input / $5 output per million tokens, ten times Luna's starting input price.
OpenAI prices batching and caching as separate discounts, Claude's standard pricing doesn't name an equivalent
OpenAI's Batch API cuts standard rates roughly in half for non-time-sensitive requests, and cached input tokens are discounted about 90% from standard input pricing. Anthropic's published API pricing for Claude doesn't list an equivalent named batch or cache discount program at this level of detail.
Claude ships its own coding agent in consumer plans, OpenAI sells a separate coding model by the token
Claude Code, a terminal and IDE coding agent, is included with Claude Pro and Max subscriptions rather than billed separately per token. OpenAI's coding-focused model, gpt-5.3-codex, is priced on its own per-token rate, $1.75 input / $14.00 output per million tokens, through the API.
Each is available on a different major cloud, not both
Claude is offered through Amazon Bedrock and Google Cloud Vertex AI, letting teams already on those clouds bill usage through their existing account. The OpenAI API is offered through the Azure OpenAI Service instead, tied to a Microsoft Azure account.
Anthropic Claude vs OpenAI API pricing
Both are billed per million tokens with no free API tier. Claude's four tiers span $1 to $10 input per million tokens; OpenAI's GPT-6 tiers span roughly $0.10 to $10 input per million tokens for short-context calls, with added batch and caching discounts.
Anthropic Claude
Haiku 4.5 costs $1 input / $5 output, Sonnet 5 costs $2 input / $10 output, Opus 5.5 costs $4 input / $20 output, and Fable 5.1 costs $10 input / $50 output, all per million tokens, with up to 1 million tokens of context on three of the four tiers.
- Free
- $0
- Pro
- $20 a month, or $17 a month billed yearly
- Max
- From $100 a month
- API: Haiku 4.5
- $1 input / $5 output per million tokens
- API: Sonnet 5
- $2 input / $10 output per million tokens
- API: Opus 5.5
- $4 input / $20 output per million tokens
- API: Fable 5.1
- $10 input / $50 output per million tokens
OpenAI API
GPT-6 Luna starts around $0.10 input / $0.50 output, GPT-6 Sol is $2.00 input / $10.00 output, and GPT-6 Astra is $10.00 input / $50.00 output per million tokens for short-context calls. Batch processing is about half price, and cached input tokens are discounted about 90%.
- GPT-6 Luna
- $0.10 input / $0.50 output per million tokens
- GPT-6 Sol
- $2.00 input / $10.00 output per million tokens
- GPT-6 Astra
- $10.00 input / $50.00 output per million tokens
- gpt-5.3-codex
- $1.75 input / $14.00 output per million tokens
- Batch processing
- About 50% off standard model rates
| Anthropic Claude | $12 on Sonnet 5 ($2 input + $10 output per million tokens) |
|---|---|
| OpenAI API | $12 on GPT-6 Sol ($2.00 input + $10.00 output per million tokens), or roughly half that using the Batch API |
Prices in USD from the official pricing pages on 28 September 2026. They change often, so confirm on claude.com and developers.openai.com before you commit.
Usage and activity
OpenAI API has 5.3 times as many GitHub stars as Anthropic Claude (11.2k against 2.1k). Weekly npm downloads: 54M for @anthropic-ai/sdk and 51M for openai. Releases on GitHub in the last 90 days: 10 for Anthropic Claude and 10 for OpenAI API.
| Measure | Anthropic Claude | OpenAI API |
|---|---|---|
| GitHub stars | 2,132 | 11,206 |
| npm downloads a week | 54M (@anthropic-ai/sdk) | 51M (openai) |
| Latest release | google-cloud-sdk…, 6 days ago | v7.30.0, 1 day ago |
| Releases in 90 days | 10 | 10 |
From the public GitHub and npm APIs, updated daily. Stars and downloads show developer interest, not product quality.
Should you choose Anthropic Claude or OpenAI API?
Choose Anthropic Claude if
- You need up to 1 million tokens of context, for example whole-repository coding or long documents
- You want a coding agent, Claude Code, included with a Pro or Max subscription rather than billed per token
- You're already on AWS or Google Cloud and want to bill usage through that account
- You want extended or adaptive thinking controls for step-by-step reasoning
Choose OpenAI API if
- You want the lowest possible starting price on a fast, high-volume model tier
- Your workload can batch non-time-sensitive requests for roughly half price
- You repeat the same context across many calls and want the cached-input discount
- You're already on Microsoft Azure and want to bill usage through that account
Switching between Anthropic Claude and OpenAI API
Both are accessed through a similar request-and-token-billing model, so switching mainly means changing SDKs, re-testing prompts for the other model family's behavior, and re-mapping context window and rate limits to the new provider's tiers. Workloads that lean on Claude's 1 million token context or OpenAI's batch and cache discounts may need real architecture changes, not just a model name swap, to get equivalent cost or capability on the other side.
Anthropic Claude vs OpenAI API: common questions
Is Claude cheaper than the OpenAI API?
It depends on the tier. OpenAI's cheapest model, GPT-6 Luna, starts lower than Claude's cheapest model, Haiku 4.5. At the top tier, Claude's Fable 5.1 and OpenAI's GPT-6 Astra are priced the same, $10 input / $50 output per million tokens.
Which has a longer context window, Claude or GPT-6?
Claude's Fable 5.1, Opus 5.5 and Sonnet 5 all support up to 1 million tokens of context at standard pricing. OpenAI's standard GPT-6 pricing covers shorter contexts, with long-context variants priced separately and higher.
Does OpenAI have a coding-specific model like Claude Code?
OpenAI offers gpt-5.3-codex, a specialized coding model billed per token through the API. Claude Code is a coding agent included with Claude Pro and Max subscriptions rather than a separately priced model.
Can I use Claude or the OpenAI API through a major cloud?
Yes. Claude is available through Amazon Bedrock and Google Cloud Vertex AI. The OpenAI API is available through the Azure OpenAI Service.
Does either API have a free tier?
No. Both the Claude API and the OpenAI API are billed per token from the first request, though the Claude consumer apps have a separate free chat plan.
Other options to consider
All ai models tools
Anthropic
AI research company that makes the Claude models, the Claude apps and the Claude API.
OpenAI
AI research company behind ChatGPT and the GPT model family, accessed through apps and an API.
Ollama
Run open source AI models locally, with an optional hosted cloud and Pro plan.
Hugging Face
Hub for open source AI models, datasets and demo apps, plus paid hosting for inference and Spaces.
Sources
More sources for each tool are on the Anthropic Claude and OpenAI API pages.
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