Evidence · first-party tested/Best AI Tools for Generating UGC-Style Video Ads With AI Avatars

The Duolingo output was generated in landscape rather than the requested vertical 9:16 short-form format.

✗ Failed🧾 artifact-verifiedinput + output shownTest date not recordedSynthesia →

What was measured

Platform formats

Correct aspect ratios and lengths for each channel or short-form platform.

context, not decisivetransformation

Aspect ratios and length presets are delivery convenience; they matter, but they do not by themselves make the ad better or worse. (3 of 3 judges)

What was given, what came back

Test input: Duolingo – Mobile App · mixed · group: ugc-style-video-ads

Input — what we sent

Input, verbatim

Product URL: https://www.duolingo.com/

Exact script:
Hook: Learning a new language has never been this easy.
Script: I've been using Duolingo for a few minutes every day, and it's made language learning simple and fun. The short lessons are easy to follow, and the daily practice keeps me motivated. If you're planning to learn a new language, give Duolingo a try.

Output requirements:
- Vertical (9:16)
- 20–30 seconds
- UGC-style AI presenter
- Natural AI voice
- Captions enabled

A short-form UGC promo prompt for a consumer mobile app, designed to test whether the tool can explain app benefits simply and persuasively while generating a realistic AI-presenter video.

Why this input is hard

· Mobile app understanding
· Consumer app promotion
· Script quality
· Avatar realism
· Voice quality
· Caption quality
· Overall ad readiness

Output — unretouched

Also checked on this input — same tool, 4 other criteria

Ad-readiness✗ FailedThe Duolingo ad was not runnable as-is because downloading required an upgraded plan and the output stayed landscape instead of vertical.Avatar realism✓ WorkedThe Duolingo output used a smooth, centered talking-head avatar, and the report says lip-sync accuracy was maintained.Script quality & persuasiveness◐ MixedThe Duolingo script explained the app benefits clearly, but the report says the presentation felt less engaging for UGC ads and had limited emotional expressiveness.Voice quality✓ WorkedThe Duolingo voice was reported as clear and well-paced, with no technical issues during generation.

Provenance

Observation: f410dd67-fcba-4ee3-ac8e-1336e9dd7204
Evidence run: 9fdbb84b-4aa0-484d-8f89-5c46608019a5
Study: Generate UGC-Style Video Ads With AI Avatars
Research task: 86baxegpg
Tested at: not recorded
Source: first-party
Evidence state: verified
Proof shown: input + output shown
Cost / latency: not captured
Repeat run: not captured
Tester: not captured

The last three rows are honest blanks, not placeholders — our capture has no field for them yet.

Query this

get_evidence({
  tool: "synthesia",
  scenario: "ugc-style-video-ads"
})

MCP · mcp.aidemos.com/api/mcp

JSON · ai.aidemos.com/v1/observations/f410dd67-fcba-4ee3-ac8e-1336e9dd7204

Free with attribution.

Same input, same check — 2 other tools

measured on Platform formats

HeyGen✓ WorkedThis is the only run that delivers the requested full-bleed vertical 9:16 frame with no letterboxing.JoggAI◐ MixedThe export format is correct at full-bleed vertical 9:16 (1080×1920), but the clip is only 13.5 seconds long, below the requested 20–30 second range.

This evidence is published in

Best AI Tools for Generating UGC-Style Video Ads With AI Avatars →

Real inputs and real outputs, no retouching · every cell queryable via API & MCP · aidemos.com