> ## Documentation Index
> Fetch the complete documentation index at: https://docs.tessact.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Animate captions

> Use layer keyframes and the Typewriter Reveal effect without damaging reading rhythm.

Caption animation should clarify timing, not compete with reading. The ordinary caption layer can be animated through supported transform and appearance properties, while **Typewriter Reveal** exposes a text-aware progress track.

## Layer-level motion

Use position, scale, rotation, dimensions, or opacity keyframes for the whole caption box. A short opacity and vertical-position entrance can establish the caption region without animating every word.

## Typewriter Reveal

Add **Typewriter Reveal** from Layer Effects. Its **Progress** parameter ranges from 0–100% and determines how much eligible caption text is revealed; **Softness** controls the reveal edge. Add keyframes to Progress for explicit reveal timing.

## Visual fades

Caption layers can display visual fade handles, but the current handle-finalization path does not reliably accept the caption type. Do not depend on those handles for a deliverable. Use opacity keyframes for a caption-layer entrance or exit and review the rendered frames.

## Timing priorities

1. Token timing matches speech.
2. Pages remain on screen long enough to read.
3. Layer motion settles before attention must move to the words.
4. Effect animation does not hide a spoken token.

<Warning>
  Avoid combining a slow typewriter progress track with word timings that already reveal text sequentially unless you have reviewed every page. Two reveal systems can multiply into missing or late words.
</Warning>

## Test protocol

Play the full caption section at normal speed, once while reading and once while watching the picture. Then frame-step the first page, a middle page boundary, and the final page. Check the H.264 output if browser text rendering or effect performance differs under load.

See [keyframe overview](/editor/animation/overview) and [easing](/editor/animation/easing).