Pasted File Editor
Simon Willison prototyped an editor that converts large pasted text into file attachments, with file opening, drag-and-drop, and image thumbnails.
Simon Willison released Pasted File Editor, a browser prototype inspired by Claude's handling of large pasted text. Instead of filling the editor with a large paste, the tool turns the content into a file attachment. It also supports opening files directly, dragging files onto the interface, and displaying images as thumbnails. Codex desktop helped build the prototype.
Simon Willison has released Pasted File Editor, a browser prototype that demonstrates the interaction pattern of "automatically converting large pasted content into a file attachment." Simon says he really likes how Claude's web version, as well as its desktop and mobile apps, handle this: when a user pastes a large amount of text at once, the interface does not expand all of the content directly into the input box, but instead recognizes it as large pasted content and presents it as a file attachment. This design keeps the input area clean and more closely mirrors how users provide documents as context.
Free shows the 3-line summary; Pro unlocks the full deep summary (~300 words) so you never have to click through.
See Pro plans →Want the original English / full article?
Read on Simon Willison's Weblog →Related
Summaries are AI-generated; the original article is authoritative.