Plannotator renders local .html and .htm files as pages by default. You can annotate visible text or point to an element without converting the page to Markdown.
Open rendered HTML
The page runs in a sandboxed iframe. Plannotator allows the page’s scripts to run inside that sandbox but does not grant it same-origin access to the annotation UI.
The sandbox does not block outbound network requests. A script in the HTML can send its own content or other data it can read to a remote server. Open only HTML you trust, or use --markdown to remove scripts before annotation.
Add HTML annotations
Use either input method in the annotation UI:
- Select visible text, then add a comment, deletion, quick label, or looks-good mark.
- Switch to pinpoint mode and select a page element that is easier to identify by position than by text.
Use the document comment action for feedback about the whole page. Send Feedback returns the annotations to the active agent or prints them to stdout when you launched the CLI directly.
Convert HTML to Markdown
Use --markdown when you want to annotate the page as converted Markdown instead of rendered HTML:
Plannotator uses Turndown with GitHub Flavored Markdown table support. It removes script, style, and noscript elements during conversion. Edits to the converted Markdown describe the requested content change, but they do not overwrite the HTML source file.
Compare HTML versions
When annotation history is enabled, reopening the same HTML file creates a new local version if the content changed. Show changes renders the current page with inline insertions and deletions for changed text. Script and style contents are not marked up by the HTML diff.
See Version history to control these local copies.
Share rendered HTML
Rendered HTML does not use the URL-only sharing format. In Export > Share, select Create short link. Plannotator prepares a portable copy, inlines eligible local support assets, encrypts the payload in your browser, and uploads only ciphertext to the configured paste service.
See Share an annotation session for the encryption and retention details.
Last verified against Plannotator OSS v0.23.1 on July 18, 2026. Maintained by the Plannotator project. 