The AI video company is adding moderation infrastructure built for AI-generated content, doubling down on a screen-at-creation model it has run since 2017.
Synthesia decides whether a video is allowed before it exists. The London AI video company, which lets users generate avatar-led clips from a script, announced on 4 June that it is extending its trust and safety stack by partnering with Cinder, a moderation-infrastructure firm built for AI-generated content. The deal reinforces a model Synthesia has run since its early days: judge the request, not the finished file.
That ordering is the distinctive part. The default for online platforms has long been detection after the fact, hosting content and waiting for it to be flagged. Synthesia assesses every script against its policies at the point of generation, before the model renders a frame.
Cinder slots into that workflow as what the company describes as an in-house agent making a second pass on every model decision, gathering context and escalating to a human reviewer only when there is a genuine judgement call. Each reviewer action retrains the system, and Cinder’s classifiers support more than 100 languages out of the box.
The 💜 of EU techThe latest rumblings from the EU tech scene, a story from our wise ol' founder Boris, and some questionable AI art. It's free, every week, in your inbox. Sign up now!The case for the partnership is volume. In 2025, Synthesia’s automated tooling reviewed more than 11.5 million pieces of content and removed 841,957 that violated its policies, with manual review handling a further 382,792 items and removing 70,272.
