Claude vs Gemini vs GPT for AI Agents: Durable Differences

Pick Claude if your agent needs its model on several major clouds or a hosted agent runtime priced by the session-hour. Pick GPT if you want a broad tier ladder and your team already works in OpenAI's stack. Pick Gemini if Google Search grounding or Google Cloud matters most.

This guide does not say which family is ahead, because that changes often. See who leads each category on the current leaderboard, which refreshes weekly. We focus on structure, plans and pricing, and we date every price.

Disclosure: eSEOspace is a member of the Claude Partner Network.

At a glance

An API price is what you pay per million tokens when software calls the model. A token is a small chunk of text, roughly a word fragment. Prices below come from vendor pages checked on 2 November 2026.

Sources: Anthropic pricing, OpenAI pricing, Google pricing.

These names and prices will age. Treat this table as a snapshot, and check the vendor page before you sign anything.

Price is not one number

Look closely at the fine print, because each vendor has traps. Google lists Gemini 4 Argon at $2 input and $10 output through 30 November 2026. From 1 December, the listed rates are $4 and $20, which doubles the bill for the same work.

Gemini 3.8 Flash follows the same pattern on 1 January 2027, moving to $1.50 and $7.50. Anthropic's Haiku 5.5 changes rate by prompt size. Prompts over 100,000 tokens cost $0.50 input and $2.50 output.

All three offer discounts for work that can wait. Anthropic and OpenAI list batch prices at half of standard, and Google describes a 50% batch reduction. If your agent runs overnight reports, that discount can matter more than the choice of family.

Caching can matter more than list price

Agents resend a lot of the same context on each step. Prompt caching stores that context so repeated reads cost less.

The three vendors structure this differently as of 2 November 2026. Claude Sonnet 5.5 reads cached input at $0.10 per million and charges $2.50 for a five-minute cache write. GPT-6.1 Sol also reads at $0.10, and charges $2.50 for a 30-minute write.

Gemini 3.8 Flash lists $0.075 for cached input, plus storage charged by the hour. So compare your real pattern, not the headline. Our cost-per-task guide shows how to run that estimate.

Reasoning tokens and long context

Advanced models think before they answer, and you usually pay for that thinking. Google's table states that output prices include thinking tokens. Anthropic's Claude Code cost guide says thinking tokens are billed as output.

Long documents are another fork. Anthropic's models page lists a 1M token context window for its Fable and Opus models. Google's models page lists 1M tokens for Gemini 4 Argon, and Gemini 3.1 Pro costs more past 200,000 tokens.

OpenAI's pricing page has separate tables for short and long context. Check which applies if your agent reads large files.

Where you can run it

Cloud access often decides this for larger companies. Anthropic lists Claude on Amazon Bedrock, Google Cloud and Microsoft Foundry, as well as its own API. That is useful if your procurement already runs through one of them.

Data location can add cost. Anthropic charges a 1.1x multiplier for US-only inference on recent models. OpenAI charges a 10% uplift for regional processing on models released on or after 5 March 2026.

Hosted agents and tools

All three vendors now sell more than a raw model. Anthropic's Managed Agents add $0.08 per session-hour on top of tokens. OpenAI's docs center on its Responses API, and its navigation includes an Agents API with hosted sandboxes.

Google's models page lists an Antigravity Agent, described as a managed agent that plans, runs code and browses in a sandbox. It also lists a Deep Research agent.

Web search costs differ too. Anthropic and OpenAI both list $10 per 1,000 searches, plus token costs. Google lists 5,000 free grounded requests a month across Gemini 3 and later, then $14 per 1,000.

For connecting tools, Anthropic's MCP connector and OpenAI's MCP tool reach remote MCP servers from the API. Google's function calling works by having your app run each function. See our guide to connecting tools for the tradeoffs.

Plans for people, not software

Your team may want chat seats as well as an API. These are monthly list prices checked on 2 November 2026.

A subscription and API billing are usually separate. Do not assume one covers the other. Anthropic also says third-party developers cannot offer claude.ai login inside their products unless previously approved, so a product you build needs API keys.

Real weaknesses to weigh

No family wins every line of a contract. Here is what each one's own pages make you think about.

• Claude: The top tier costs the same as GPT-6 Astra, and Claude Code usage climbs fast in long sessions. Haiku's low rate applies only to prompts up to 100,000 tokens.
• GPT: OpenAI uses Fast and Ultrafast price modes, which cost more than standard. Model names and availability move often, so pinned models can need migration work.
• Gemini: Listed price increases are already scheduled, so a budget built today can be wrong in weeks. Caching adds hourly storage charges on many models.

How to use the benchmarks

Use leaderboards to build a shortlist, not to pick a winner. Read the methodology first. Then check the knowledge work board or the coding board, depending on your job.

Our take: pick two families, run your own tasks on both, and record cost and success together. A model that wins a benchmark can still lose on your data. Our agent scorecard gives you a template.

Questions to ask before you commit

A price table cannot answer everything. Before you sign, get clear answers to these questions, ideally in writing.

• How long will the model you pick stay available, and how much notice do you get before retirement?
• What rate limits apply at your expected volume, and how do you raise them?
• Is your data used for training on this plan, and how long is it kept?
• Which regions can process your data, and what does that add to the bill?
• If you buy through a cloud marketplace, do the same prices and features apply?

Keep the answers with your contract, because vendors change their terms. Then run a small test with real volume. Rate limits and latency often show up only under load, and they will not appear on any leaderboard.

Which should you choose

Choose Claude if you want the same model across Bedrock, Google Cloud and Foundry, or a hosted runtime with a simple session-hour fee.

Choose GPT if your staff already use ChatGPT, or you want a clear ladder from Luna up to Astra with priced speed options.

Choose Gemini if search grounding is central to the job, or your data and contracts already sit in Google Cloud. Budget using the post-increase prices, not today's.

For a high-volume task, also price the small tiers first. Haiku 5.5 and GPT-6 Luna list the same $0.10 and $0.50 as of 2 November 2026. Many agent steps do not need a top model, so route simple steps down.

Frequently asked questions