The editor
Edit a canvas's files in the browser, preview your changes, then publish when ready — no local setup, no build step. The editor lives in the canvas's Editor tab.
Drafts and publishing
Every canvas has one draft: a working copy separate from what viewers see. When you open a new canvas's draft it starts empty; otherwise it's seeded from the current published version. Your edits autosave to the draft as you go (debounced, with a final flush when you leave the editor); the canvas keeps serving its published version until you explicitly publish.
The loop:
- Edit files in the draft. Changes autosave; nothing viewers see changes yet.
- Preview the draft to check it before publishing.
- Publish when ready. This snapshots the draft into a new immutable version and points the canvas at it.
Publishing and rollback require the canvas to be active: while it's archived or
disabled by an admin, both are blocked (409 NOT_ACTIVE). You can still edit the draft.
Files
Use the file tree to add, rename, replace, delete, and upload files (drag-and-drop
works too). Relative paths are preserved, so a css/site.css reference resolves
the way you'd expect.
Name your home page index.html at the canvas root. The root URL serves index.html
if it exists; if the draft has exactly one HTML file it's served as the entry even
under another name; but with multiple HTML files and no index.html, the canvas root
returns 404. Drafts in that state get a repair notice pointing you toward a valid
index.html.
Text files open in the CodeMirror editor with syntax highlighting. Binary assets (images, fonts, spreadsheets) aren't text-editable: images show a preview, and any non-editable file offers Download and Replace instead of an edit surface. You can publish any non-empty draft.
Limits per canvas: 25 MB per file, 100 MB total, 2000 files. Edits that would exceed a limit are rejected.
Preview and on-page editing
The live preview pane (owner-only, collapsible and expandable to fullscreen) renders the current draft, not the published version, so you see exactly what publishing would ship. For JavaScript-driven drafts the inline pane can't run ES modules or make authenticated SDK calls, so it swaps to an Open full preview link that opens the draft in its own context.
Two editing surfaces:
- Code (CodeMirror) — the default, available for any draft.
- Page text — edit the copy directly in the rendered page; it saves back to that HTML file. Available only when the draft is a single HTML page with no JavaScript. Anything else (multiple HTML files, or a page that runs JavaScript) uses Code mode, and the editor falls back to Code automatically if on-page editing stops being available.
Versions, rollback, and restore
Each publish is an immutable version. canvas-drop keeps the last 10 versions; older ones are pruned.
From the Versions tab you can:
- See version history with the source (editor, folder, ZIP, paste, the deploy API, or a staged upload), when it was published, file count, and total size.
- Make any version the served one with the Make current button (confirm in the dialog). It re-points the canvas to that version — forward or back — as a guarded pointer swap, so visitors get it immediately.
To pick up editing from an earlier version, use Edit this version: it loads a published version back into the draft so you can change it and publish again. If the draft already has unpublished changes, you're prompted to confirm before they're discarded. Making a version current changes what visitors see; editing a version changes what's in your draft.
Storage is content-addressed: files are keyed by content hash, so unchanged files across versions are stored once and only changed files are written.
See also Create & publish for the non-editor paths (folder, ZIP, paste, deploy API).