Beyond Prompt AI Studio

Comparisons

Closed-source LLMs compared

Five proprietary LLM APIs, scored uniformly on the same seven criteria - with a source link and date for every entry, so you can verify the numbers yourself. This category is aimed at developers and technical decision-makers building an application on an API - not end users of a finished chat app (see our "AI Chat Assistants" category for that). Switch between the individual and business perspective at the top of the table. At the bottom you'll find scenario recommendations instead of a single "winner": which API fits depends on your specific situation.

A comparison of closed-source LLM APIs weighs offerings like GPT, Claude, Gemini, Grok and Cohere from a developer's perspective - from price per token to rate limits to enterprise SLAs - for anyone building their own application on an API.

How we score
View for
Scores stay the same - only strengths, weaknesses, and the verdict adapt to the perspective.

Last data review: 07/05/2026, 06:00 PM

Which tool fits you?

Coding- and analysis-heavy applications

Claude (API)

The highest benchmark score in this comparison, the origin of the MCP standard for tool integrations.

Multimodal applications from a single provider

Gemini (API)

The broadest multimodality (image, video, audio, image generation) and the best certification standing.

Maximum cost efficiency on API calls

Grok (API)

The cheapest flagship pricing among the closed APIs.

Key takeaways

  • Claude (API) scores highest on benchmarks in this comparison and originated the MCP standard for tool integrations - particularly strong for coding and analysis.
  • Gemini (API) offers the broadest multimodality (image, video, audio, image generation) and the best certification coverage among the five APIs.
  • Grok (API) has the cheapest flagship pricing among the closed-source APIs.
  • Cohere is the only option with true private/on-premise deployment - relevant for regulated industries with strict data-sovereignty requirements.
  • GPT (API) has the most mature overall ecosystem, with the most granular pricing tiers and enterprise SLA via the Scale Tier.

Self-host, use an API, or buy a ready-made solution? Build vs. buy vs. API

Frequently asked questions

Which LLM API is best for coding applications?

Claude (API) scores highest on benchmarks for coding and analysis tasks in this comparison and originated the MCP (Model Context Protocol) standard for tool integrations.

Which LLM API is the cheapest?

Grok (API) has the cheapest flagship pricing per million tokens among the closed-source APIs.

Is there an LLM API with on-premise deployment for regulated industries?

Cohere is the only option among the five closed-source APIs compared with true private/on-premise deployment - relevant for industries with strict data-sovereignty or compliance requirements that rule out a cloud API.

What's the difference between this category and "AI Chat Assistants"?

This category evaluates APIs from a developer's perspective (price per token, context window, SDKs, rate limits) for building custom applications. The "AI Chat Assistants" category instead compares the finished consumer chat apps (ChatGPT, Claude.ai, the Gemini app, etc.) for end users.