# Marker
URL: https://remocn.dev/docs/captions/components/caption-marker

Plain captions where the words that matter get a highlighter swipe the moment they are spoken

- Install: `npx shadcn@latest add @remocn/caption-marker`
- Vibe: paper
- Natural length: transcript-driven

## Installation

```bash
npx shadcn@latest add @remocn/caption-marker
```

## Usage

`CaptionMarker` takes a timed transcript and renders only the text block, so
place it inside your own `AbsoluteFill`. Words read as a plain caption line
until a word from `keywords` is spoken. Then a slightly tilted highlighter band
draws behind it from left to right, taking as long as the word itself, and the
covered letters switch to `markerTextColor` so they stay readable on the band.
The band stays until the page leaves. Without `keywords`, nothing is marked.
See [Positioning](/docs/captions/getting-started/positioning) for safe
placements and [Get a transcript](/docs/captions/getting-started/get-a-transcript)
for producing `captions.json`.

```tsx
import { AbsoluteFill } from "remotion";
import { CaptionMarker } from "@/components/remocn/caption-marker";
import captions from "./captions.json";

export const MyScene = () => (
  <AbsoluteFill
    style={{
      justifyContent: "flex-end",
      alignItems: "center",
      paddingBottom: 108,
      paddingInline: 192,
    }}
  >
    <CaptionMarker
      captions={captions}
      keywords={["thing", "lose", "three", "captions", "sound"]}
    />
  </AbsoluteFill>
);
```

Keywords match whole words, ignoring case and punctuation, so `"sound"` also
catches `Sound,` and `sound.` in the transcript.

## Props

| Prop | Type | Default | Description |
|---|---|---|---|
| `captions` | `Caption[]` | `—` | The timed transcript, in the `Caption` shape from `@remotion/captions`. Times are relative to the start of the surrounding `Sequence`. |
| `keywords` | `string[]` | `—` | Words that get the highlighter. Matched per word, ignoring case and punctuation. When omitted, no word is marked. |
| `markerColor` | `string` | `"#facc15"` | Colour of the highlighter band. |
| `markerTextColor` | `string` | `"#0a0a0a"` | Colour of the letters the band has covered, so a marked word stays readable. |
| `combineTokensWithinMilliseconds` | `number` | `1200` | How much speech one page may span before the next word starts a new page. Pages also break at the end of a sentence and on any pause of at least `holdMs` (300 ms minimum). |
| `holdMs` | `number` | `600` | How long a page stays after its last word when the next page is not already due. It fades out at the end of the hold instead of hanging through the pause. |
| `fontSize` | `number` | `64` | Font size in pixels. |
| `fontWeight` | `number` | `800` | Font weight. The font itself is inherited. |
| `color` | `string` | `"#ffffff"` | Colour of unmarked words. |
| `shadow` | `boolean` | `true` | A tight text shadow that keeps unmarked words legible over bright footage. It fades out under a word as the band covers it. |
| `className` | `string` | `—` | Classes for the text block — width, font family, `uppercase`. |

## Use when
- Talking-head or explainer video where a few words carry the point — the marker lands on exactly those words, in time with the voice, and leaves the rest calm.
- You want the hand-made feel of a highlighter pen on top of an ordinary, readable caption line.

## Don't use when
- Every word should be marked as it is spoken, not just the keywords — use `caption-highlight-box`, whose box travels across the whole phrase.
- There is no voiceover and the highlighted line is scripted on-screen copy — use `marker-highlight`.
- You want the spoken position shown on every word without singling any out — use `caption-karaoke`.