---
title: "Subscript and superscript"
description: "How subscript and superscript marks round-trip between DOCX and Tiptap."
canonical_url: "https://tiptap.dev/docs/conversion/content-types/text-and-formatting/subscript-superscript"
---

# Subscript and superscript

How subscript and superscript marks round-trip between DOCX and Tiptap.

Subscript and superscript marks round-trip between DOCX and Tiptap. Content like H₂O imports, renders in the editor, and exports back to DOCX with formatting preserved.

## What you need

- **Extensions:** [ConvertKit](https://tiptap.dev/docs/conversion/import/docx/convertkit.md) — `Subscript` and `Superscript` are bundled and enabled by default.
- **Configuration:** None required beyond registering ConvertKit.

## Support overview

|             | Import    | Editor                   | Export    |
| ----------- | --------- | ------------------------ | --------- |
| Subscript   | Supported | Supported via ConvertKit | Supported |
| Superscript | Supported | Supported via ConvertKit | Supported |

## Import

Import subscript and superscript using the [editor extension](https://tiptap.dev/docs/conversion/import/docx/editor-extension.md) or the [REST API](https://tiptap.dev/docs/conversion/import/docx/rest-api.md). Both produce identical output.

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

| Word element                      | Tiptap mark   |
| --------------------------------- | ------------- |
| `<w:vertAlign val="subscript">`   | `subscript`   |
| `<w:vertAlign val="superscript">` | `superscript` |

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

## Editor rendering

[ConvertKit](https://tiptap.dev/docs/conversion/import/docx/convertkit.md) bundles both [`Subscript`](https://tiptap.dev/docs/editor/extensions/marks/subscript.md) and [`Superscript`](https://tiptap.dev/docs/editor/extensions/marks/superscript.md) and enables them by default — no separate install required.

```ts
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:

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

> **Disabling either one drops imported marks:**
>
> When you set `subscript: false` or `superscript: false`, marks of that type from imported DOCX
> will not be recognised by the editor schema. See the
> [invalid schema guide](https://tiptap.dev/docs/guides/invalid-schema.md) for how to manage unrecognised marks.

## Export

Both the [editor extension](https://tiptap.dev/docs/conversion/export/docx/editor-extension.md) and the [REST API](https://tiptap.dev/docs/conversion/export/docx/rest-api.md) export subscript and superscript marks back to DOCX run properties:

| Tiptap mark   | Word element                      |
| ------------- | --------------------------------- |
| `subscript`   | `<w:vertAlign val="subscript">`   |
| `superscript` | `<w:vertAlign val="superscript">` |

Chemical formulas (H₂O, CO₂), mathematical notation (x², E=mc²), and footnote references all round-trip without loss.

Subscript and superscript within math or LaTeX expressions follow a separate code path (using OOXML math elements `m:sSub` and `m:sSup`).