Synthesia Not Working?
Synthesia video export stuck, avatar lip sync off, API returning 401 or 422, voice quality poor, or content policy issues? Check live status and fix it fast.
Synthesia — live status
Updated every 5 minutes. Full history at prismix.dev/service/synthesia.
What's wrong? Diagnose fast
Video export stuck
Processing time: short clip = 2–5 min. 10+ min video = up to 30–45 min. Refresh My Videos — exports complete silently. Duplicate and re-export if stuck beyond 45 minutes.
Avatar lip sync off
Use sentences under 15 words. Add commas/periods for pacing. Use the pronunciation editor for technical terms. Spell out acronyms (A-I not AI). Preview audio before full render.
API 401 / 422 error
401 = invalid key. Header must be Authorization: Token YOUR_KEY (not Bearer). 422 = invalid avatar/voice ID — list available IDs in workspace Assets. Regenerate key in workspace settings.
Voice quality poor
Preview voices in the voice browser before committing. Use punctuation for pacing. For custom voice clones: 15–30 min clean audio, professional mic, no background noise.
Content policy block
Synthesia blocks political content, adult content, and video designed to deceive. For business use, the platform has strict compliance policies. Check the error message for the specific flag.
Subscription / billing issues
Check subscription status at app.synthesia.io → settings → Billing. Synthesia is enterprise-focused: Starter plan, Creator, and Enterprise. Video generation limits vary significantly by plan.
Synthesia API quick reference
Create a video
POST https://api.synthesia.io/v2/videos
Authorization: Token YOUR_API_KEY
Content-Type: application/json
{
"title": "Product Demo",
"scriptBySlides": [{
"avatar": "anna_costume1_cameraA",
"script": "Welcome to our product demo.",
"voice": "en-US-JennyNeural",
"background": "green_screen"
}]
} Poll video status
GET https://api.synthesia.io/v2/videos/{id}
Authorization: Token YOUR_API_KEY
# status: "in_progress" | "complete" | "failed"
# When complete: response includes "download" URL Step-by-step fix
- 1
Check live Synthesia status
Visit prismix.dev/service/synthesia. If Synthesia is operational, most issues are export processing times — not platform bugs. Refresh My Videos section rather than waiting on the progress screen.
- 2
Fix stuck video export
Refresh app.synthesia.io — video may have completed. Go to My Videos. Processing time: 2–5 min for short clips, 15–45 min for 10+ minute videos. If stuck beyond 45 minutes: duplicate the project (three-dot menu → Duplicate), then re-export the duplicate. This forces a fresh render.
- 3
Fix lip sync quality
For better avatar lip sync: (1) write sentences under 15 words; (2) use periods and commas to add natural pacing; (3) use the Pronunciation editor for acronyms and company names; (4) spell out acronyms — "A-I" syncs better than "AI"; (5) use the script preview (speaker icon) to hear audio before generating the full video.
- 4
Fix API authentication errors
401 error: confirm the header format is
Authorization: Token YOUR_KEY— notBearer. Regenerate key in workspace settings if 401 persists.
422 error: avatar ID or voice ID does not exist in your plan. List available avatars: GET /v2/avatars. List voices: GET /v2/voices. Use the exact ID string from those responses. - 5
Improve voice quality
Use the voice browser in the Synthesia editor to preview voices before committing. For enterprise custom voice clones: record 15–30 minutes of clean speech with a professional microphone, no background noise, in a treated room. Custom voice clones require the Enterprise plan. Add punctuation in the script to control pacing — long run-on sentences produce flat delivery.
Get alerted when Synthesia goes down
Star Synthesia on Prismix and get emailed the moment status changes. Free, no credit card.
Frequently asked questions
Why is Synthesia not working?
Synthesia not working: (1) video still exporting (2–45 min depending on length); (2) lip sync issue (use short sentences, punctuation, pronunciation editor); (3) API 401 (Token not Bearer); (4) 422 invalid avatar/voice ID; (5) platform outage (check prismix.dev/service/synthesia).
Is Synthesia down right now?
Check prismix.dev/service/synthesia for live status. Video export slowness is common and not necessarily a true outage.
Synthesia video export stuck — when does it finish?
Processing times: under 2 min of video output = 2–5 min export. 5–10 min output = 10–20 min. 10+ min = 30–45 min. Refresh My Videos. If stuck beyond 45 minutes, duplicate the project and re-export.
Synthesia API 401 — how to fix?
API 401: the header must be Authorization: Token YOUR_KEY (not Authorization: Bearer YOUR_KEY). Regenerate the API key in workspace settings if 401 persists after fixing the header format.
Synthesia avatar lip sync is poor — how to improve?
Improve lip sync: sentences under 15 words, punctuation for pacing, pronunciation editor for acronyms/proper nouns, spell out acronyms (A-I not AI), use script preview before full render. Slow or medium speaking pace in voice settings produces more accurate sync than fast.
