Claude Opus 4.6 User Guide: Model Selection, Attachment Uploading, and Account Switching

This tutorial focuses specifically on how to use Claude Opus 4.6: from entering a chat and selecting the model, to uploading attachments, organizing conversations, and switching accounts safely. Many people get stuck on “can’t find the Claude Opus 4.6 entry point” or “can’t send attachments.” If you follow the steps below, you’ll basically be able to get started smoothly.

Enter a chat and select the Claude Opus 4.6 model

First, open Claude’s official portal in your browser and log in to your account. After entering the chat page, start a new chat. Near the chat box there is usually a “Model” dropdown option. Click it and select Claude Opus 4.6 (it will appear here only if your account has access to the model).

After selecting Claude Opus 4.6, it’s recommended to send a short prompt first to confirm it’s active, such as “Summarize what I’m about to send in bullet points.” If you switch to another conversation and then come back, remember to check whether the model is still Claude Opus 4.6 to avoid using the wrong model across different chats.

The right way to upload attachments and paste materials with Claude Opus 4.6

When you need Claude Opus 4.6 to read a document, prioritize using the attachment button (often a paperclip icon) to upload the file, and in the same message describe the task: what to extract and what the output format should be. After uploading, don’t rush to send multiple follow-up instructions—wait for the attachment to finish parsing before continuing, which is more stable.

If it’s only a small amount of text, you can paste it directly into the message, but it’s recommended to split it into sections and add small headings so Claude Opus 4.6 can follow the structure more easily. If an attachment upload fails, try switching networks or reducing the file size, then retry—this is usually more effective than repeatedly refreshing.

Conversation management: renaming, searching, and an export workflow

After using Claude Opus 4.6 for a while, you’ll accumulate many conversations. It’s recommended to rename important chats promptly, using titles that include the project name and task keywords, for example “Contract Review – Clause Risk Points.” When you need to look something up, using keyword search in the sidebar is much faster than manually scrolling through history.

If you want to use Claude Opus 4.6’s conclusions in a document or presentation, ask it to organize the output directly in a three-part structure: “Conclusion – Evidence – Items to Confirm,” then copy it into your note-taking tool. This both preserves the reasoning trail and makes it easier for you to proofread and implement.

Switching accounts and logging out safely: avoiding account mix-ups and permission confusion

When using multiple accounts with Claude Opus 4.6, the most reliable approach is to log out of the current account via the avatar/account menu first, then log in to another account—avoid hard-switching across multiple tabs. It’s best to separate a work account and a personal account using different browser profiles or an incognito window to reduce the chance of permissions and history getting mixed together.

When using Claude Opus 4.6 on a public computer, be sure to “Log out” when finished, and clear browser cache and autofill data. If you suddenly can’t see Claude Opus 4.6 in the model list, first confirm whether you switched to the wrong account or a different workspace, then check your subscription/permission status.