What Synthesia documents about speech

Synthesia (docs.synthesia.io) publishes a voice catalogue in which every entry carries a language name, a language code, a gender and a voice id, and states that lip sync and facial expressions are generated from the spoken content. As of 2026-09-22.

Inclusion rule. Fields are the same five for every model here; a field the vendor does not document is recorded as not documented rather than inferred from generated output. Order. Fixed field order, identical on every model page.

1A language list a schedule can be built on

Instead of a number in a paragraph, this vendor publishes rows: the formal language name, the native name, a language code, a gender, a voice name and an id. A planner can compare that list between quarters, pick a market off it, and pass the id straight into a request.

The register records it as a catalogue rather than a count, because the difference is operational. A count tells a planner the capability exists somewhere; a list with codes tells them whether the market they were asked about is inside it.

2Lip sync is tied to the script, and comes with a condition

Lip sync and facial expressions are generated from the spoken content, which places this entry with the models that derive the mouth from the words rather than repairing it afterwards. Then the documentation adds something almost unheard of here: lip sync performs best when the avatar is framed closer in the scene rather than positioned far from the camera.

That sentence is a shot-list instruction wearing the clothes of a help note. It says the weak case is the wide shot, which is precisely the shot a director reaches for when two people are in a scene together.

3A cloned voice has its own reach

Voice cloning carries a language list of its own, running from Afrikaans to Zulu and described as the same list used for standalone cloning. So the question is not only which languages the platform speaks but which of them a particular voice can speak, and the two lists are kept separately.

What is not published is how a voice stays attached to a character across a run of videos. An id can be reused; nothing states that the pairing is held anywhere except in a production's own notes.

4This entry, one column at a time

Each of these stays inside a single field: what Synthesia puts there, what the wording settles, and what it leaves for a take to answer.

• Audio source — from the script, or uploaded.
• Voice source — a catalogue voice, or a cloned one.
• Per-character binding — not documented by the vendor.
• Languages — a catalogue with codes.
• Lip-sync — the spoken content, framed close.

5Read against another entry

Each of these puts Synthesia beside one other entry on a column where the two land at opposite grades of answer.

• Synthesia and sync-3 — on languages.
• Synthesia and D-ID — on lip-sync.
• HeyGen and Synthesia — on languages.
• Kling AI and Synthesia — on lip-sync.
• SceneMixer and Synthesia — on languages.
• Hedra and Synthesia — on lip-sync.

6Where this model sits against the rest

Inclusion rule. Models whose vendor documents something about generated speech. A model with nothing published on the point is still listed, with the cell marked hollow. Order. Alphabetical by model name.

Inclusion rule. Models whose vendor documents something about generated speech. A model with nothing published on the point is still listed, with the cell marked hollow. Order. Alphabetical by model name.

Inclusion rule. Models whose vendor documents something about generated speech. A model with nothing published on the point is still listed, with the cell marked hollow. Order. Alphabetical by model name.

7Sources

Taken from the voices reference and avatar documentation at docs.synthesia.io on 2026-09-22. Every entry against the same five fields sits on the speech controls page; the rule behind each field is on how read. The entries either side of this one: Veo, Vidu.

• Languages
  Each voice is listed with its formal and native language name, a language code, a gender, a name and a voice idpublished as a catalogue with codesSynthesia, list of supported voices / recorded 2026-09-22
• Lip-sync
  Lip sync and facial expressions are generated from the spoken contentdriven by the scriptSynthesia, create an avatar / recorded 2026-09-22
• A framing condition attached to lip-sync
  Lip sync performs best when the avatar is framed closer in the scene rather than positioned far from the cameraSynthesia, create an avatar / recorded 2026-09-22
• Voice source
  Voice cloning carries a language list of its own, running from Afrikaans to Zulu and described as the same list used for standalone cloninga cloned voice with its own reachSynthesia, create an avatar / recorded 2026-09-22