Files and images in chat

Attach with the clip, or paste an image straight into the box. Up to 8 files go with one message.

Where an attachment goesImages are scaled down and sent with the message. Text files go into the message up to about 100,000 characters; larger ones stay in the container and the model reads them in parts. Other files are stored in the container and the model gets only their path.ImageText, up to100,000 charsText, over100,000 charsOther fileYou attach a fileor paste an imageScaled to 1536 px,sent with themessageText goes inthe messageKept in thecontainerStored in thecontainer, only thepath is sentModel gets path,lines and outline,reads parts
What happens to a file depends on its type and, for text, on its size.
Diagram as text
  1. You attach a file with the clip or paste an image. A message carries up to 8 attachments.
  2. An image is scaled down to at most 1536 px on its long edge and sent with the message, so a vision-capable model sees the picture.
  3. A text file of up to about 100,000 characters goes into the message as text.
  4. A text file over about 100,000 characters stays in the container. The model gets its path, line count and an outline, then reads the parts it needs.
  5. Any other file, such as a PDF or an Office document, is stored in the container and the model gets only its path.

Files uploaded to a chat may be checked for known malware. This check looks at the file, not your chat messages. A clean result cannot guarantee that a file is safe.

Text files
are read into the message
Images
go to vision-capable models
Other files
go to the container

It stays with the chat

Attachments are stored with the chat, so the model can refer back to them later.

Large files stay in the container

A text file over about 100,000 characters is not put into the message. It is kept in the container, and the model gets its path, line count and an outline, then reads the parts it needs. That is cheaper, because it does not read the whole file every turn. Files that are not text, such as PDFs or Office documents, go to the container too, and the model gets only their path. You can also put any file there yourself.

Sent with the message

Pasting a long text and pressing Enter at once sends the file with the message. Sending reads the live list of attachments, not the last drawn page.

In research and Ultracode runs

Deep Research and Ultracode runs take the files of the chat along as an attached brief. A file too large for the prompt appears as an outline, its first lines and its path under /work/uploads, and the agents read the rest in the container. Images are named but not described, because the planning models read text only. Only files of your own chat are used.

What the model reads each turn

Attached to the chat

Turn 1
Turn 2
Turn 3

The whole file, every turn.

Read from the container

Turn 1
Turn 2
Turn 3

Only the part it needs.

The bars sketch the idea. They are not measured sizes.