By Anthropic
Claude Opus 5.5
A Claude Opus model for long coding sessions and expert knowledge work
Price per message
4.5 PMCper message(KRW 180)
Shown as x4.5 in the chat.
With previous-conversation memory off: 3.5 PMC (KRW 140)
Anything extra, such as input beyond the included length, attachments or paid web search, is added up and shown on the send button before you send.
1 PMC is based on KRW 40, and a payment fee is added when you buy PMC (for example, 100 PMC costs KRW 4,476).
Features
- Shows a reasoning summary by default
- Web search +1.75 PMC
- Photo input
- PDF and document input
Try it
Start from an example
- List the test cases for a sign-up feature
- Which clauses in a lease should a tenant always check
- Break down the cost of opening a small cafe item by item
Nothing is sent when you click. You review the message in the chat and are charged only when you send it yourself. You can look around without signing in; you sign in when you send.
Sign up and verify your email to get 7.5 bonus PMC, enough for 1 messages with this model at its base price (bonus valid for 90 days).
Good for
- Planning clean-ups and refactors that span several files
- Reading long documents like contracts or papers carefully and listing the key issues
- Problems where several possibilities need weighing before answering
Good to know
- PDFs are read as extracted text only, so tables, charts and scanned images are not reflected in answers.
- Web search costs extra only when turned on. With it off, the model answers from what it knew as of its knowledge cutoff.
- It always reasons before answering, so even short questions can take a while to start.
Specifications
- Provider
- Anthropic
- Released
- September 22, 2026
- Input included per message
- Up to 2,000 characters (extra input is charged)
- Knowledge cutoff
- June 2026
- Input types
- Text, Photos, Files
- PDF handling
- Reads extracted text only
- Web search
- Extra charge when turned on (1.75)
- Reasoning
- Always on
- Multiplier
- x4.5
Sources
- Provider model documentation (checked 2026-10-15)
Compare with other Anthropic models
Prices are the base price per message (memory on, no attachments or search).
| Model | Per message | Reasoning summary | Web search |
|---|---|---|---|
| Claude Opus 4.5 | 3 PMC | No | +2 PMC |
| Claude Opus 4.6 | 3 PMC | No | +2 PMC |
| Claude Opus 4.7 | 3.5 PMC | No | +2 PMC |
| Claude Opus 4.8 | 3.5 PMC | No | +2 PMC |
| Claude Opus 5.5 (This model) | 4.5 PMC | Shown | +1.75 PMC |
| Claude Opus 5 | 5.5 PMC | Shown | +2 PMC |
FAQ
- How much does one message cost?
- The base price is 4.5 PMC (KRW 180) per message, shown as x4.5 in the chat. With previous-conversation memory turned off, it is 3.5 PMC (KRW 140). Anything extra, such as input beyond the included length, attachments or paid web search, is added up and shown on the send button before you send.
- Do I need a monthly subscription?
- No. There is no monthly subscription: you top up PMC and only what you use is deducted each time you send. 1 PMC is based on KRW 40, and a payment fee is added when you buy PMC (for example, 100 PMC costs KRW 4,476).
- Can it search the web?
- Yes. If you turn web search on when sending, 1.75 PMC is added to that message.
- Can I upload photos or files?
- Yes. You can send photos as well as PDFs and document files. If a file costs extra, the amount is shown on the send button before you send.
- Can I see a reasoning summary?
- Yes. A short summary of what it worked through before answering is shown by default, at no extra charge.
- Can I attach long documents?
- Yes. You can attach PDFs and document files, and the file charge is added to the total shown on the send button before you send. If you need to work with a very long document as a whole, also look at the long-context (pay-as-you-go) models in the chat.