Runway's voice documentation, read route by route

Runway documents two routes to a voice. A sample runs from ten seconds to five minutes, at most ten megabytes; a description needs twenty characters or more naming tone, accent, pacing and personality. The voice is created asynchronously, previewed once ready, and then referred to by its own id, with custom clones listed from the Pro plan. From 3 source pages, read 2026-09-12 to 2026-10-13; no maker pays to be listed.

1What these notes already record

Runway's recorded lines about custom voices, beside what this register holds about describing a voice, auditioning one, and keeping one on a character.

• Voice source
  A custom voice can be built from an audio sample between 10 seconds and 5 minutes long and at most 10 MBa published sample windowRunway, custom voices reference / recorded 2026-09-22
• Voice source
  A voice can instead be asked for in words, with the description required to run at least 20 charactersa route that needs no recordingRunway, custom voices reference / recorded 2026-09-22
• Per-character binding
  A voice is created asynchronously, reaches a ready state with a preview, and is then referred to by its own ida stored voice objectRunway, custom voices reference / recorded 2026-09-22
• Lip-sync
  Not documented by the vendor (as of 2026-09-22)not addressed where voices are definedRunway, custom voices reference / recorded 2026-09-22
• Asking for an accent
  A voice designed from a description should name tone, accent, pacing and personalityRunway, custom voices reference / recorded 2026-10-13
• A voice written in words
  By default each character's voice is a line of description, covering age, weight, pace and where it sits, which the video model performsSceneMixer, character voices guide / recorded 2026-10-13
• Hearing a voice before using it
  Every preset in the library has a sample to play in the picker, and matching or changing a match costs nothingSceneMixer, character voices guide / recorded 2026-10-13
• Per-character binding
  A voice matched to a character from the built-in preset library is used as reference audio on every shot that character speaks ina matched preset kept on the characterSceneMixer, character voices guide / recorded 2026-10-13
• Voice source
  The guide tells users to use a preset voice library or their own recordingstwo routes namedSceneMixer, compliance guide / recorded 2026-09-12

2Two routes into a stored voice, and what each one fixes

The reference for custom voices spells out both ways in. A sample of recorded speech between ten seconds and five minutes, no larger than ten megabytes, is the route that copies a voice that already exists. A description of at least twenty characters, naming tone, accent, pacing and personality, is the route that writes one instead, with no session and no recording.

The two fixes differ in kind. A sample settles timbre the moment it is taken, and carries whatever the take carried with it. A description fixes what it names and leaves everything else to the model, which is why the reference tells the writer what the description should cover: tone, accent, pacing, personality — the four things a voice keeps across a season, listed on the page that creates it.

3A voice that becomes an object with an id

Neither route produces sound. Creation runs asynchronously, the voice reaches a ready state with a preview, and from then on it is referred to by an id of its own. That is the shape a series wants: the casting decision is made once, and later shots point at the result instead of re-describing it.

An id records which voice, not where it came from. The pages read do not keep the sample beside the voice it produced, so a production holding several clones ends up keeping its own record of which clip became which speaker — nothing in the output announces it, and a voice rebuilt from the wrong half of a session sounds like a stranger.

4What the pages leave open where voices are defined

This register records that lip-sync is not documented by the vendor in the place where voices are defined. The reference is about building and storing a voice; what a mouth does once that voice speaks is not addressed there. The question in this page's heading runs straight into the gap: footage of a real face speaking arrives with a mouth already on screen, and the page that defines the voice does not say how the two are met.

The plan boundary is written down, at least: custom voice clones are listed from the Pro plan upward, so the route belongs to the higher tiers even though the voice itself is a property of the account rather than of a shot. What the tiers do not change is the shape of the route, which is the part this register records.

5Persistence, and the two places a voice can live

Runway stores the voice; the pipeline these notes read attaches it. In that pipeline, a preset matched to a character rides with every shot the character speaks in, while the character's default voice is a line of description the model performs until a preset or a recording takes over. One arrangement keeps the voice in an account-level object; the other keeps it on the character and moves with the scene.

What a series asks of either is the same thing: that the voice survive the tenth episode. The register's two lines on that are the audition and the binding — presets can be played before one is matched and matching costs nothing, and a matched preset stays on the character afterwards. Runway's equivalent of both is the ready state and the id, which are documented and are not the same promise as a preview button.

6What each of them prints about a spoken line

Inclusion rule. Rows are the makers this page is about, each read on its own public page, plus one pipeline whose spoken controls this register records line by line. A maker's cell carries the wording of the page read; the pipeline's cell is one sentence quoted from its published guides. A point a page leaves open is recorded as left open rather than filled in. Order. Alphabetical by maker.

7What the collected threads counted

Both numbers below are Runway's, and the two quotations kept from the material are questions asked around its plans and its pricing.

Inclusion rule. Names carried in the collection and read on this page. A post arguing with itself can be counted in both the positive and the negative column. Order. Descending by posts.

Does signing up for Runway feel like getting ripped off?

r/runwayml, collected 2026-10-14

Is the Runway Unlimited annual plan at 50% off worth it?

r/runwayml, collected 2026-10-14

8When the other tool would serve better

• The voice should be copied from a real recording — A sample of ten seconds to five minutes, within ten megabytes, is the route that clones a voice that exists rather than describing one.
• A voice has to be built once and reused across projects — The voice becomes an object of its own, created asynchronously, previewed at the ready state and referred to afterwards by its id.
• The cast is directed in writing rather than recorded — A description of twenty characters or more that names tone, accent, pacing and personality needs no session and no sample.

Searches like "What is the advantage of shooting interviews or talking heads this way?" land here. Read beside it: Kling motion control and MagicLight voice cloning.