Cheapest way to use Claude Opus 5.5: $0.007 an answer by batch, $20 a month to chat

What is the cheapest way to use Claude Opus?

Ten routes reach Claude Opus. Per answer, they differ about 34 times over: from $0.007 on the Batch API to $0.24 for a flat message on a monthly plan. Three of the ten publish no per answer price at all. Each is priced below on one standard answer, 1,000 tokens in and 500 out, as of 3 October 2026.

All of the Opus 5.5 rows are new. Anthropic's launch post of 22 September 2026 says "Input and output tokens are $4 and $20 per million, 20% less than Opus 5." The guides ranking for this question in early October 2026 still price Opus 5 at $5 and $25, a $0.0175 standard answer. One of them even tells readers that the Free plan includes Opus. It isn't on Anthropic's pricing page. Every API figure above is from Anthropic's pricing docs, read on 3 October 2026.

Opus by the token wins until one message carries about 22,500 tokens

Paying by the token is cheapest for short messages. A flat price per message is cheapest for long ones, and you can work out where they cross. With a 500 token reply, an Opus 5.5 message on the API costs 1 cent plus 0.4 cents for every thousand input tokens. A flat Opus message on Whizi's Powerhouse plan costs 10 cents on the monthly price, because 10,000 credits for $49.99 buy 500 Opus messages at 20 credits each. Opus starts on Pro, where 2,500 credits for $29.99 buy 125 of them at 24 cents, so the API list price stays cheaper there at every size up to 40,000 tokens.

The lines cross at 22,500 input tokens on the monthly plan and at 15,000 tokens on the yearly one, where a message works out to 7 cents. The Batch API stays below the monthly rate all the way to 40,000 tokens, the largest input a Whizi message takes, and below the yearly one until about 32,500.

Three things can move the crossing point. In a chat, every turn resends the whole conversation, so turn twenty of a thread that started with a pasted report can carry 22,500 tokens on its own. Caching moves it the other way. Opus 5.5 reads cached input at $0.20 per million, 5% of the input price. A client that caches the history pays 0.6 cents to re-read 30,000 tokens, so the API stays cheaper at almost any length. Thinking pulls it down. Opus 5.5 always thinks and the thinking bills as output, so a 2,000 token reply moves the monthly crossover down to about 15,000 input tokens. Anthropic also notes that its newer tokenizer "produces approximately 30% more tokens for the same text" than Sonnet 4.6 and earlier. If you made your token estimate on an older Claude, it's about 30% short.

Can you use Claude Opus for free?

No. As of 3 October 2026 Anthropic's pricing page lists Sonnet and Haiku on the Free plan and adds Opus at Pro. There's no free Opus in the Claude apps. The API has a small trial. Anthropic's pricing FAQ says "New users receive a small amount of free credits to test the API", but it doesn't state an amount. That's enough to try Opus 5.5 at $0.014 an answer, and not enough to work with it.

Anything that's sold as free unlimited Opus is a trial balance or someone else's account. The cheapest way to use ChatGPT and Claude together covers why a shared or resold login is a risk rather than a discount. Whizi doesn't have a free Opus either. Its free tier is limited to its own house model and Auto.

How much does Claude Opus cost per month?

Claude Opus costs $20 a month on Claude Pro, $17 a month billed yearly, $100 on Max 5x and $200 on Max 20x. On the API you pay only for what you send: $0.014 per standard Opus 5.5 answer. That makes the subscription a bet on how much you send. $20 is the API list price of about 1,430 standard answers, roughly 47 a day, or about 2,860 through the Batch API. If you send fewer, the API is cheaper. If you send more, Pro is, as long as you stay inside its five hour windows.

Pro and Max carry a second meter for the weeks when your plan runs out. Anthropic's help center says "Usage credits are billed at standard API rates" (manage usage credits). Its usage bundles sell $50 of credit for $45, $250 for $200 and $1,000 for $700, up to $2,000 of bundles a month. At the 30% bundle a standard Opus 5.5 answer costs $0.0098. That undercuts the API list price and still costs 40% more than batch.

Max buys more of the same Opus, not a better one. Claude Pro vs Claude Max has the signals that say you need the multiplier, and Claude usage limit reached has the fixes to try before you pay for it.

Five ways to cut an Opus API bill without changing models

The cheapest Opus 5.5 setup is the Batch API with a cached prompt and the default effort. Each of the steps below is a setting, not a new vendor.

1. Batch anything that can wait. Anthropic's docs say the Batch API runs requests "with a 50% discount on both input and output tokens", so Opus 5.5 drops to $2 and $10 per million. Overnight summaries, document sorting and test generation all fit.
2. Cache the repeated part. A 5 minute cache write costs $5 per million on Opus 5.5 and every read after it costs $0.20, so a system prompt or a reference document sent with every request is paid for once at near full price and then at 5%.
3. Leave effort at medium, or lower it. Opus 5.5 defaults to medium effort and its thinking cannot be switched off, so the effort setting is the cost control. Low suits lookups and rewrites.
4. Start a new thread when the topic changes. Every turn resends the conversation, and a long thread is where the per token bill climbs past a flat plan.
5. Send the easy turns to Sonnet 5.5. At $2 in and $10 out it is half the Opus 5.5 rate, and Opus can be kept for the step that needs it.

Three settings raise it instead. Fast mode doubles it to $8 and $40. US only inference adds 10% on the Claude API, and the regional endpoints on Amazon Bedrock and Google Cloud carry a 10% premium over their global ones.

What OpenRouter, Poe and Whizi add on top of Anthropic's price

OpenRouter adds a fee when you top up, and nothing per token. Its FAQ says "We pass through the pricing of the underlying providers without any markup". Its model list on 3 October 2026 showed Claude Opus 5.5 at $4 and $20, plus a batch variant at $2 and $10. You pay 5.5% on card top ups, with a $0.80 minimum. That turns a $0.014 answer into about $0.0148, and in exchange you get one key that also reaches GPT, Gemini and the rest.

Poe has an Opus 5.5 bot live at poe.com/Claude-Opus-5.5, but its per message rate shows only after sign in. Poe's public API price list on 3 October 2026 went no further than Claude Opus 4.8, at $4.29 in and $21.46 out per million. That's $0.015 a standard answer for the older model, more than Opus 5.5 costs at Anthropic's list price. Poe sells points, from 10,000 a day up to 8.25 million a month. Its purchase FAQ says unused points don't roll over unless a plan says so. Is Poe AI worth it converts its points to dollars.

Whizi charges per message instead of per token. Claude Opus 5.5 costs 20 credits a message whatever the message holds, up to 40,000 input and 20,000 output tokens. Claude Opus starts on Pro: $29.99 a month or $19.99 billed yearly for 2,500 credits. That's 125 Opus messages, alongside GPT, Gemini, Grok and the rest of the curated Pro list. Powerhouse, $49.99 a month or $34.99 billed yearly, gives 10,000 credits, which is 500 Opus messages across the full 280+ catalog. The chart shows where Whizi loses: even on Powerhouse a short Opus question costs 10 cents here against 1.4 cents on the API. The price doesn't fall when a message is short, cached or able to wait. Claude Code also stays with Anthropic. It wins if you send long Opus turns from a chat window, want a bill that can't run past $29.99 or $49.99, and also use other vendors' models. The Claude in Whizi docs list the credit price of every Claude model.