GPT-6 Sol vs Claude Sonnet 5.5 vs Gemini: API Price Comparison

Updated November 4, 2026

Mid-tier models from the big providers now cluster around the same price. The details below decide who is actually cheaper for you.

List prices per million tokens (input / output)

Same workload, monthly cost

Assume 1,000 requests a day, 1,500 input and 400 output tokens each, over 30 days. That is 45 million input and 12 million output tokens a month.

The ranking depends on your input-to-output ratio. Output-heavy workloads favor providers with a low output price, such as Grok and Mistral.

What the list price hides

• GPT-6 Sol bills the whole request at $4 / $15 once a prompt passes 272,000 tokens.
• Gemini 3.1 Pro rises above 200,000 tokens.
• Claude Sonnet 5.5 keeps one rate across its 1 million token window.
• Gemini 4 Argon doubles in December.

Quality also differs. A cheaper model that needs two attempts costs more than a pricier one that succeeds once.

Why the input-to-output ratio decides the winner

Providers set very different output prices relative to input. GPT-6 Sol and Claude Sonnet 5.5 charge five times more for output than input. Gemini 3.1 Pro charges six times more. Grok 4.5 charges three times more, and Mistral Large 4 about three times. If your app writes a lot, those differences add up.

Scenario 1: input-heavy retrieval

Say you answer questions over documents: 5,000 input and 200 output tokens per request, 1,000 requests a day, 30 days. That is 150 million input and 6 million output tokens a month.

Scenario 2: output-heavy writing

Now 500 input and 2,000 output tokens per request, same volume. That is 15 million input and 60 million output tokens a month.

The spread between cheapest and most expensive grows from about $140 to almost $480, simply because the workload changed.

The Gemini 4 Argon countdown

Gemini 4 Argon is priced at $2 / $10 through November 30, 2026, and doubles to $4 / $20 on December 1. On our standard workload of 45 million input and 12 million output tokens, that moves the monthly cost from about $210 to about $420. If you plan to build on it, budget at the higher price.

Premium and budget tiers

At the top, Claude Fable 5.1 and GPT-6 Astra are both listed at $10 / $50. At the bottom, Claude Haiku 5.5 and GPT-6 Luna are both $0.10 / $0.50, and Gemini 3.8 Flash sits slightly higher at $0.75 / $3.75. Match the tier to the job rather than defaulting to one provider.

Beyond the price tag

Price is one factor. Also compare context length (all three flagships offer roughly one million tokens), speed, tool support, rate limits, data handling and how well each model does on your own tasks. A model that is 10% cheaper but fails 10% more often is not cheaper. Build a small test set from your real inputs and score every candidate before you decide.

Frequently asked questions

Which is cheaper, GPT-6 Sol or Claude Sonnet 5.5?

At list price they are identical, $2 input and $10 output. Differences come from caching, batch rates, long-prompt rules and how many tokens each model uses to finish a task.

Does one provider use fewer tokens?

Models differ in verbosity and in how much they reason. Measure tokens per completed task on your own data, not just the price per token.

Should I use several providers?

Many teams do, routing each task to the best value model. The cost is more integration work, which a gateway can reduce.

Try it with your numbers

Open the LLM API cost calculator, enter your own request volume and token counts, and compare all of these side by side.

Prices checked November 4, 2026; verify with each provider before committing.

Check the source: official pricing pages: Anthropic · OpenAI · Google Gemini · xAI · Mistral · DeepSeek · Amazon Bedrock · Cohere. See our methodology.