Last updated: 2026-08-19
Sync Labs is a developer API for lip sync and video dubbing, offering five models that range from a fast general-purpose default to sync-3, its 4K-native flagship that auto-detects hands, microphones, and glasses blocking the mouth. It targets developers wiring dubbing into apps via REST and SDKs, not end-user video editors.
About Sync Labs
Sync Labs (sync.so) is a lip sync and visual dubbing API built by Synchronicity Labs Inc. for developers, giving programmatic access to lip sync models through a REST API and Python/TypeScript SDKs, plus a web-based Studio playground for testing before writing code. The platform offers five lip sync models spanning a quality and speed trade-off. sync-3 is the flagship: native 4K output with built-in obstruction detection for hands, microphones, and glasses, handling extreme camera angles and full-shot processing without manual masking. lipsync-2-pro adds diffusion-based super-resolution for fine facial detail like beards and teeth. lipsync-2 is the fast, general-purpose default, and lipsync-1.9.0-beta is the legacy budget option. react-1 layers facial expression and head motion on top of standard lip movement, capped to short clips per generation. Billing combines a monthly subscription, which sets maximum clip duration, concurrency, and voice-clone slots, with separate per-second usage charges that vary by model and are invoiced once they cross a plan-specific threshold. The cost FAQ below covers exact per-second and subscription rates. Developer tooling includes a REST API at api.sync.so, a Python SDK (pip install syncsdk), a TypeScript SDK (npm i @sync.so/sdk), and a documented OpenAPI 3.1 spec. Active speaker detection and a bring-your-own TTS API key become available from the Creator tier up; team workspaces appear on the Growth and Scale plans.
Pricing
Free tier: 3 generations/month (20s max lipsync, 15s max sync-3), watermark. Hobbyist $5/mo (1min, 1 concurrent, 3 voice clones, watermark). Creator $19/mo (5min, 3 concurrent, 5 voice clones, no watermark, own TTS API key). Growth $49/mo (10min, 6 concurrent, 15 voice clones, 5% discount, Batch API, 3 seats). Scale $249/mo (30min, 15 concurrent, 50 voice clones, 20% discount, Batch API, 5 seats, delegated support). Enterprise custom. Per-second usage billed separately: lipsync-2 $0.04–$0.05/sec, lipsync-2-pro $0.067–$0.083/sec, sync-3 $0.107–$0.133/sec, lipsync-1.9.0-beta $0.02–$0.025/sec, react-1 $0.133–$0.167/sec. Growth 5% off, Scale 20% off. Invoice thresholds: Hobbyist $6, Creator $20, Growth $50, Scale $250.
Key Features
- Multi-Model Lip Sync Family: Five production models from a legacy budget option to sync-3, the flagship, each tuned for a different quality-versus-speed trade-off.
- 4K Native Output with Obstruction Detection: sync-3 outputs native 4K and automatically detects hands, microphones, and glasses blocking the mouth, handling extreme angles and full shots without manual masking.
- Subscription Plus Usage Billing: A monthly subscription unlocks duration, concurrency, and voice-clone limits; usage is billed separately per output second by model, with invoice thresholds so charges never hit mid-generation.
- Developer-First: API, SDKs, OpenAPI Spec: REST API at api.sync.so, typed Python and TypeScript SDKs, a Studio playground, and a published OpenAPI 3.1 spec make integration a documented process rather than reverse-engineering.
- Visual Dubbing and Voice Cloning: react-1 layers in facial expression and head motion; voice cloning, active speaker detection, and a bring-your-own TTS key become available progressively on higher tiers.
Pros
- Five-model lineup covers every quality, speed, and budget need in one API, from a legacy fast option to the obstruction-aware sync-3 flagship.
- Pay-per-second usage with transparent per-model rates and invoice thresholds means no credits or prepay, and no surprise mid-month bills.
- Developer-first: typed SDKs, a documented REST API, an OpenAPI spec, and a Studio playground for testing before you write code.
- sync-3's built-in obstruction detection handles hands, microphones, and glasses blocking the mouth without manual masking, something most competing lip-sync APIs still need post-processing for.
- Subscription tiers scale cleanly from Free through Enterprise, with clear feature gates like watermark removal, team seats, and Batch API at each step.
Cons
- react-1 requires a paid subscription; it isn't available on Free or Hobbyist.
- The cheapest paid tier still watermarks your output; removing it requires stepping up to Creator.
- lipsync-2 and lipsync-2-pro can't open a mouth that starts fully closed in the source video; only sync-3 handles that.
- Obstruction detection ships built-in only on sync-3; it's optional on lipsync-2 and lipsync-2-pro.
- Two separate charges (subscription plus per-second usage) make total cost less predictable than a single flat price.
Frequently Asked Questions
What does Sync Labs actually cost?
Sync Labs uses a subscription plus usage model. Subscriptions run Free ($0, 3 gens/mo), Hobbyist $5/mo, Creator $19/mo, Growth $49/mo, Scale $249/mo, and custom Enterprise. Usage is billed per second of output at model-specific rates ranging $0.02-$0.167/sec, with Growth getting 5% off and Scale 20% off. There's no credit prepay; you're invoiced once usage crosses your tier's threshold.
What do you get on Sync Labs's free tier?
Three generations a month come free, capped at 20 seconds for lipsync models or 15 seconds for sync-3, running on a single concurrent job with a watermark on every output. No payment details are required, though the allowance is built for testing quality rather than production use.
Which tools compete with Sync Labs in 2026?
Vidu and Runway Gen-3 are full video-generation platforms worth it if you need more than lip sync: Vidu for reference-to-video consistency with native audio, Runway Gen-3 for camera control and broader creative tools. HeyGen and Synthesia are avatar-video platforms with templates and per-video pricing, a better fit if you don't want to touch an API.
Is Sync Labs better than HeyGen?
HeyGen is a template-driven avatar platform billed per finished video; Sync Labs is a raw API billed per second of processed output across five lip-sync models, including a 4K obstruction-aware model HeyGen doesn't offer. Pick HeyGen for ready-made avatars with no code; pick Sync Labs to integrate lip-sync into your own app or pipeline.
What does it take to start using Sync Labs?
Sign up free at sync.so, no credit card required, to test model quality on the free tier first. From there, grab an API key and call the REST endpoint directly, or install the Python SDK (pip install syncsdk) or TypeScript SDK (npm i @sync.so/sdk) to integrate programmatically. The Studio playground at sync.so/studio lets you preview results before writing any code.
Top Alternatives
- Vidu: A programmatic lip-sync API with multiple models and pay-per-second billing is Sync Labs' territory; end-user video generation with reference-to-video consistency and native audio co-generation is Vidu's.
- HeyGen: A developer API with pay-per-second billing and model choice is Sync Labs' pitch; avatar-based video with template workflows and per-video pricing is HeyGen's.
- Synthesia: A raw lip-sync API with model choice and pay-per-second billing describes Sync Labs; a full avatar video platform with templates, SCORM export, and LMS integrations describes Synthesia.
- Runway Gen-3: A specialized lip-sync API with model choice keeps Sync Labs focused; general video generation with camera control, Act-One, and broader creative tools is Runway Gen-3's scope.