The chat composer

What it is

The composer is the text box at the bottom of any chat. Most of the power you’ll use day-to-day is reachable from here: attaching files, turning on a skill, switching the model, swapping to a different writing style. Everything is two clicks or one keystroke away.

Three menus shape what Claude does with what you type: the + button on the left (files, skills, connectors, modes), the / slash command in the text itself (type-to-filter across commands and skills), and the model picker on the right.

Where to find it

On desktop

Default view on the Chat tab. Cmd-N starts a fresh one.
Apple Intelligence Writing Tools appear in the Edit menu while the composer is focused.

On the web

Any chat view on claude.ai. The home page (/new) drops you straight into an empty composer.

How to use it

Attach or extend what Claude can do

Click the + on the left of the composer to open a vertical menu:

Add files or photos — open the OS file picker. See also File creation for what Claude can produce back.
Add to project — attach the current chat to a Project.
Add from GitHub — pull in repo context (desktop; on web, requires a connected GitHub connector).
Skills › — submenu listing installed skills. Click Manage skills to open the Customize → Skills page.
Connectors › — per-connector toggles (Gmail, Google Calendar, Notion, etc.). Click Manage connectors or Add connector to jump to the manager.
Plugins — the plugin manager entry point.
Research — Research mode (deep multi-step research runs).
Web search — checked by default.
Use style › — Normal, Learning, Concise, Explanatory, Formal, plus Create & edit styles (see Customize).

The slash palette (power-user shortcut)

Type / in the composer and an inline palette appears at the cursor. It filters across commands and skills together — start typing skill-creator, add-files, schedule, and so on. This is the keyboard-driven equivalent of the + menu and is faster once you know the names.

Pick a model

The model picker on the right of the composer shows:

Opus 4.7 — most capable. Default.
Sonnet 4.6 — most efficient for everyday tasks.
Haiku 4.5 — fastest, for quick answers.
Adaptive thinking toggle — lets Claude think longer on complex prompts.
More models › — access to Opus 4.6, Opus 3, Sonnet 4.5 for legacy/comparison work.

You can switch model mid-conversation. The next turn will use whatever’s currently selected.

Upload files

Click + → Add files or photos, pick from the OS file picker, or just drag-and-drop onto the composer. You can also paste images directly from the clipboard.

Supported formats:

Documents: PDF, DOCX, CSV, TXT, HTML, ODT, RTF, EPUB, JSON. XLSX is supported but requires code execution and file creation to be enabled in your account.
Images: JPEG, PNG, GIF, WebP.

Limits in a single chat:

30 MB per file.
Up to 20 files per chat.
Images up to 8000×8000 pixels (use 1000×1000 or larger for best results).

PDF behaviour: Claude analyses text and visuals (charts, images, graphics) in PDFs under 100 pages. PDFs over 1000 pages are processed as text only. When referring to a page, use the PDF viewer’s page number, not the printed page number.

Non-PDF documents: text extraction only — embedded images inside a DOCX or slide deck aren’t read.

Project files follow the same 30 MB per-file limit but have no per-project count limit; total content must still fit the context window (RAG kicks in for large projects — see Projects).

Good to know

Dictation mic sits on the far right of the composer. Talk instead of type.
Seeded prompt chips (Write, Learn, Code, From Calendar, From Gmail) appear above/below the composer and rotate alongside the placeholder.
Drag and drop files works anywhere on the composer.
On desktop, the Edit menu exposes Apple Intelligence tools (Proofread, Rewrite, Summarise) for the text you’re drafting.
British English is used for accounts in UK locale (e.g. “Summarise”, “Centre”).

What’s changed recently

2026-04-18 — Cross-referenced with official help-center articles; added sources.
2026-04-18 — Page verified against desktop build 1.3109.0. Model picker lists Opus 4.7 as default.