HeyGen suits marketing and social videos, with realistic avatars, video translation and lip sync. Synthesia suits corporate training and internal communication, with team workspaces and admin controls. If you can't decide, run the same short script through both in one afternoon and judge the lip sync, voice, editing and export.
Here's my quick verdict before the detail. If you're making videos to sell, promote or post on social, start with HeyGen. If you're making training, onboarding or internal updates for a team, start with Synthesia.
You don't need weeks of reading reviews to choose between them. You need one afternoon, one real script and a fair way to judge what comes out. Both tools turn a script into a video with an AI presenter, so on paper they look alike. The difference is who they're built for, and that shows up fast once you use them side by side.
The short difference
HeyGen: marketing, social and translation
HeyGen is built with marketers, founders and creators in mind. It's known for realistic avatars, the option to create a custom avatar of yourself, and video translation that dubs your voice into another language and matches your lip movements to the new audio. If you post short videos on LinkedIn, Instagram or YouTube, or you want one video in several languages, that's where it shines.
Synthesia: training, learning and teams
Synthesia has focused on companies making training and internal communication videos. It's known for a large library of stock avatars and languages, templates built for training content, and workspace features for teams, such as shared brand settings, collaboration and the admin and security controls that larger organisations expect. If your videos end up in a learning platform rather than a social feed, it fits that world.
What they share
Both turn typed text into a talking presenter, both let you add your logo, captions and backgrounds, and both have stock avatars you can use on day one without filming anything. So the question isn't whether either can make a decent video. It's which one fits the way your business makes and shares video.
An afternoon test plan
Both tools have offered a free plan or trial, so check the current options, then work through these steps in order. Keep everything the same except the tool.
- Write one real script. Aim for 60 to 90 seconds. Use something you'd publish, like a product explainer or a welcome message for new staff, not a test sentence.
- Pick the same avatar style. Choose a similar presenter, framing and background in both, so you're comparing the tools rather than the casting.
- Use the same language and accent. If you sell in more than one market, make a second version in your other main language too.
- Judge the lip sync. Watch the mouth on words with p, b and m sounds. Play it full screen, because small problems hide on a phone.
- Judge the voice. Listen for pace, pauses and how it handles your brand name and any industry terms. Try each tool's pronunciation fixes.
- Judge the editing. Change one line of script, swap the background and add your logo. Note how long each change takes.
- Judge the export. Download in the format you'll use, then check captions, social aspect ratios and how the file looks once it's uploaded.
Score each step out of five while it's fresh. By the end of the afternoon, the right tool is usually obvious, and you've got a usable first video either way.
One thing I wouldn't judge in a single afternoon is the cost of each finished video. Both tools count usage in their own way, by minutes, credits or plan limits, so once you know which one you prefer, read the current plans and work out what a normal month of videos would need before you sign up.
HeyGen vs Synthesia at a glance
| What you get | HeyGen | Synthesia |
|---|---|---|
| Built for | Marketing, sales and social video | Training, onboarding and internal comms |
| Avatars | Realistic stock avatars plus custom avatars | Large stock library plus custom avatars |
| Languages | Video translation with lip sync | Many languages for script-to-video |
| Team features | Team plans available | Workspaces, collaboration and admin controls |
| Best first test | A social post or sales video | A training module or company update |
| Check before buying | How many video minutes or credits your plan includes | Which features sit on which plan |
Who should pick which
Pick HeyGen if you're a founder, coach, consultant or marketer who wants to show up on video more often without filming every week, or if you want to reach customers in other languages with the same message.
Pick Synthesia if you work in HR, learning and development or operations, you're producing training for a team, and you care about consistency, sign-off and access control more than social flair.
Want AI doing the heavy lifting in your marketing?
I build the systems that handle the boring 80 percent, so you get your week back. Done properly, with the human kept in.
And sometimes, pick neither. If your audience needs to see the real you, a short video filmed on your phone often builds more trust than a polished avatar. In my experience working with small businesses, avatars work best for the content you'd never get round to filming, not as a full replacement for you.
If you're a small team that does both, marketing videos and staff training, let the most frequent job decide. Whichever kind of video you'll make every week is the one the tool should be built for.
If you're still weighing up options, my roundup of the best AI avatar generators covers more tools, and my comparison of the best AI video generators for social media looks at short-form video in particular.
Make an AI video or avatar tool? See how to get it featured on this list.
Ethics: consent and disclosure for AI avatars
This part matters more than any feature table. An AI avatar uses someone's face and voice, so treat it with the same care you'd give a signed photo release.
- Only create an avatar with consent. Both tools build in consent steps for custom avatars, and you should keep your own written record too.
- Agree what happens when someone leaves. If a team member's avatar appears in your training videos, decide in advance whether you'll keep using it.
- Tell viewers when a presenter is AI. A short line on screen or in the caption is usually enough, and some platforms require a label.
- Don't put words in real people's mouths. Never make an avatar of a client, a public figure or anyone who hasn't agreed to it.
- Check the rules where you operate. Laws on likeness and AI disclosure differ by country and keep changing, so ask a legal professional if you're unsure.
Frequently asked questions
Is HeyGen or Synthesia better?
HeyGen is usually the better fit for marketing and social videos, and Synthesia for training and internal communication. Test both with the same script to decide.
Can HeyGen and Synthesia translate videos?
HeyGen is known for video translation with lip sync. Synthesia supports many languages for script-to-video. Check the current features for the languages you need.
Do I need permission to create a custom AI avatar?
Yes. You need the person's consent, and both tools ask for consent before they create a custom avatar.
Should I tell viewers a video uses an AI avatar?
Yes. A short note on screen or in the caption keeps trust, and some platforms require a label.
