# CodeDiff > Props, semantics, themes, and optional imports for CodeDiff. **Source:** [https://diff.svelte.page/docs/api/code-diff](https://diff.svelte.page/docs/api/code-diff) --- The optional Svelte entry exports the same component as default and named `CodeDiff`, plus the public `CodeDiffProps` type: ```typescript import CodeDiff, { CodeDiff as NamedCodeDiff, type CodeDiffProps } from '@humanspeak/svelte-diff/code' ``` Install `@tanstack/highlight@1.0.0` when using this entry. The ordinary package root does not re-export CodeDiff or load TanStack at runtime. | Prop | Type | Default | Behavior | | ------------------- | -------------------------------------- | -------------------- | ----------------------------------------------- | | `originalText` | `string` | required | Complete literal original source | | `modifiedText` | `string` | required | Complete literal modified source | | `highlighter` | `Pick` | required | Caller-created complete-source tokenizer | | `language` | `string` | `'plaintext'` | Registered language name or alias | | `diffMode` | `'character' \| 'word' \| 'line'` | `'word'` | Raw comparison unit | | `timeout` | `number` | `1` | Diff deadline in seconds; 0 unlimited | | `cleanupSemantic` | `boolean` | `false` | Character-mode semantic cleanup | | `cleanupEfficiency` | `number` | `0` | Character-mode efficiency edit cost; 0 disables | | `class` | `string` | `''` | Additional outer `pre` classes | | `ariaLabel` | `string` | `'Code differences'` | Accessible overflow-region name | | `rendererClasses` | `{ remove?: string; insert?: string }` | `{}` | Additional `del`/`ins` classes | ```svelte {themeCss} ``` `Highlighter` is imported as a type from `@tanstack/highlight/core`. Register individual languages yourself; no all-language root import is needed. Both complete sources are tokenized before diff composition. Removed runs use original tokens; equal and inserted runs use modified tokens. The single `pre.th-code.svelte-code-diff` contains `code`, operation wrappers with `data-diff="remove|insert|equal"`, and syntax spans with `th-*` classes. Text is natively escaped by Svelte. Change backgrounds default to translucent red/green through `--svelte-diff-remove-bg` / `--svelte-diff-insert-bg`. Syntax foreground belongs to caller theme CSS, and default changed text has no strike-through. The block uses `white-space: pre` and keyboard-accessible overflow. Expected patterns are always false and are not a prop. There are no callbacks, custom snippets, patch inputs, gutters, or headless API in this entry. Cleanup applies only to character mode. Work remains synchronous and preserves model source code units; browser SSR parsing can normalize CR/CRLF. See the [code diffs guide](/docs/guides/code-diffs) for caching, themes, and limits.