> ## Documentation Index
> Fetch the complete documentation index at: https://rendobar-docs-compose-nature-clips.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Animated word-level captions

> Generate animated word-level captions from a video, with 11 style presets, custom fonts, auto-emphasis, and translation.

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The `captions.animate` job returns a video with word-level animated captions burned in. Speech is automatically transcribed, segmented into timed cues, and rendered as styled subtitles burned onto the source.

<Info>
  **Accepts:** video · **Type:** `captions.animate`
</Info>

## Request

<CodeGroup>
  ```ts SDK theme={null}
  import { createClient, outputUrl } from "@rendobar/sdk";

  const client = createClient({ apiKey: "rb_YOUR_KEY" });

  const job = await client.jobs.create({
    type: "captions.animate",
    inputs: {
      source: "https://cdn.rendobar.com/assets/examples/sample.mp4",
    },
    params: { preset: "hormozi", mode: "balanced" },
  });

  const result = await client.jobs.wait(job.id);
  console.log(outputUrl(result));
  ```

  ```python Python theme={null}
  import requests
  res = requests.post(
      "https://api.rendobar.com/jobs",
      headers={"Authorization": "Bearer rb_YOUR_KEY"},
      json={
          "type": "captions.animate",
          "inputs": {
              "source": "https://cdn.rendobar.com/assets/examples/sample.mp4",
          },
          "params": {
              "preset": "hormozi",
              "mode": "balanced",
          },
      },
  )
  ```

  ```bash cURL theme={null}
  curl -X POST https://api.rendobar.com/jobs \
    -H "Authorization: Bearer rb_YOUR_KEY" \
    -H "Content-Type: application/json" \
    -d '{
      "type": "captions.animate",
      "inputs": {
        "source": "https://cdn.rendobar.com/assets/examples/sample.mp4"
      },
      "params": {
        "preset": "hormozi",
        "mode": "balanced"
      }
    }'
  ```
</CodeGroup>

## Parameters

<ParamField body="preset" type="enum" default="hormozi">
  Built-in caption style. One of: `hormozi`, `mrbeast`, `tiktok`, `pill`, `karaoke`, `word-pop`, `minimal`, `subtitle-block`, `neon`, `gold`, `reveal`.
</ParamField>

<ParamField body="language" type="string">
  ISO-639-1 language hint (e.g. `en`, `es`). Absent = English. Non-English forces the `large-v3-turbo` model regardless of `mode`.
</ParamField>

<ParamField body="mode" type="enum" default="balanced">
  Speed-vs-accuracy tradeoff for transcription.

  * `fast`: `base.en`, English only, \~3× faster, \~7-9% WER
  * `balanced`: `small.en`, default, \~5-7% WER
  * `accurate`: `large-v3-turbo`, \~3× slower, \~3-4% WER
</ParamField>

<ParamField body="style" type="object">
  Style overrides layered on top of `preset`. Any field set here wins. Unset fields fall through to the preset. Key fields:

  * `font`: font family name. A [bundled family](#fonts) or the family name of a custom font you pass via the `font` input.
  * `layout`: `phrase` (up to two balanced lines) or `word` (one word at a time).
  * `position`: `top`, `center`, or `bottom`.
  * `entrance`: `fade`, `pop`, or `bounce`. Each word reveals at its spoken moment.
  * `highlight`: active-word treatment. `{ "mode": "color" | "box", "color": "#RRGGBB", "textColor": "#RRGGBB", "scale": 100-200 }`.
  * `fill`, `stroke`, `shadow`, `bold`, `case`, `marginV`: colour, outline, and weight controls.
</ParamField>

<ParamField body="autoEmphasis" type="boolean" default="false">
  Let an in-stack model mark the important words so they render in the accent colour (the "gold words" look).
</ParamField>

<ParamField body="translateTo" type="enum">
  Translate captions before animating. One of `es`, `fr`, `de`, `pt`, `it`, `nl`. Omit to keep the original language.
</ParamField>

<ParamField body="captionData" type="boolean" default="false">
  Also return the word-level transcript plus SRT and VTT on `output.data`.
</ParamField>

## Inputs

<ParamField body="source" type="string" required>
  URL of the source video. An uploaded asset's content URL works too.
</ParamField>

<ParamField body="subtitles" type="string">
  URL of an SRT or VTT file. When provided, its text is animated and transcription is skipped.
</ParamField>

<ParamField body="font" type="string">
  URL of a TTF or OTF font file. Set `style.font` to that font's family name to render captions in it. See [Fonts](#fonts).
</ParamField>

## Fonts

Eleven presets ship with sensible default fonts. To pick a different one, set `style.font` to a bundled family. No upload needed.

| Bundled family | Pass as `style.font` |
| -------------- | -------------------- |
| Inter          | `"Inter"`            |
| Bebas Neue     | `"Bebas Neue"`       |
| Anton          | `"Anton"`            |
| Montserrat     | `"Montserrat"`       |
| Poppins        | `"Poppins"`          |
| Roboto         | `"Roboto"`           |
| Oswald         | `"Oswald"`           |

To use your own font, pass two values together:

1. The font file URL as the `font` input.
2. The font's real family name as `style.font`.

```json theme={null}
{
  "type": "captions.animate",
  "inputs": {
    "source": "https://cdn.rendobar.com/assets/examples/sample.mp4",
    "font": "https://example.com/MyBrand.ttf"
  },
  "params": {
    "preset": "gold",
    "style": { "font": "My Brand" }
  }
}
```

`style.font` must match the family name baked into the file, not the filename or URL. If it does not match, the renderer falls back to the preset font.

Like every job, this returns the standard response. See [Job output](/concepts/job#the-output) for the shape and how to read the result.

To burn existing subtitles instead, see [caption.burn](/jobs/captions/burn).