Subscript and superscript

Subscript and superscript marks import from DOCX and render in the editor, but are not preserved on export. Content like H₂O will import and display correctly but export as plain H2O.

What you need

• Extensions: ConvertKit — Subscript and Superscript are bundled and enabled by default.
• Configuration: None required beyond registering ConvertKit.

Support overview

Import

Import subscript and superscript using the editor extension or the REST API. Both produce identical output.

The conversion service reads <w:vertAlign> run properties and produces the corresponding marks:

Chemical formulas (H₂O, CO₂), mathematical notation (x², E=mc²), and footnote references all import correctly.

Editor rendering

ConvertKit bundles both Subscript and Superscript and enables them by default — no separate install required.

import { ConvertKit } from '@tiptap-pro/extension-convert-kit'

const editor = new Editor({
  extensions: [ConvertKit],
})

Subscript renders as <sub>, superscript renders as <sup>. Keyboard shortcuts: Cmd+, for subscript, Cmd+. for superscript.

If you don't want one of them, disable it through ConvertKit's configuration:

ConvertKit.configure({
  subscript: false,   // disable subscript
  superscript: false, // disable superscript
})

Export

Neither the editor extension nor the REST API exports subscript or superscript marks.

Subscript and superscript applied in the editor work correctly for display. The limitation only affects export to DOCX.

Subscript and superscript within math or LaTeX expressions follow a separate code path (using OOXML math elements m:sSub and m:sSup) and are not affected by this limitation.