Popper documentation (archive)

These are the docs that were hosted on popper.js.org, which has been decommissioned. They are preserved here in plain Markdown so the Popper v1 and v2 reference material stays available to people who have not migrated to Floating UI yet.

Popper is the predecessor to Floating UI. For new code, use the Floating UI docs instead — nothing in this repository describes the current library.

Note

This is a read-only archive. Popper is no longer maintained, and these documents are not updated — they record the library as it was documented when the site was retired.

Finding a page from an old link

The folder layout mirrors the old site's URLs, so an old link maps directly onto a file. popper.js.org/docs/v2/modifiers/flip/ is docs/v2/modifiers/flip.md; a URL ending at a directory is that folder's index.md.

Contents

• docs/v2/ — Popper 2 (@popperjs/core): constructors, lifecycle, modifiers, utils, tutorial, and the v1 → v2 migration guide
• docs/v1/ — Popper 1 (popper.js) API reference
• react-popper/v2/ — the react-popper wrapper: the usePopper hook, render props, portals, and typings

What changed in the conversion

These files were MDX pages rendered by a Gatsby site. Converting them to plain Markdown meant dropping the parts that only existed at build time:

• Frontmatter (navigationLabel, order, redirect_from) — replaced by a regular # Heading on each page
• Interactive demo components (<OffsetDemo>, <FlipDemo>, and the tutorial's <ResultN> embeds) — these needed a live React runtime. The surrounding prose and code samples that explain each behaviour are unchanged
• Ad placeholders, and the __UNPKG_CDN_URL__ build variable, which is now written out as https://unpkg.com/@popperjs/core@2

Internal links were repointed at the corresponding .md files, since the old site served every page at a directory URL. All code samples are preserved verbatim.