Synthesia Review: AI Avatars So Real I Got Spooked

If you’ve ever had to make a training video, you know the annoying part isn’t writing the script. It’s finding someone to present it, setting up a camera, recording multiple takes, and then doing it all over again when something changes.

That’s the problem AI video generators like Synthesia are built to solve. It lets you turn a script into a presenter-led video without a camera or real presenter, then update it by changing the text instead of reshooting. Synthesia says more than 90% of Fortune 100 companies use the platform, which gives you a pretty good idea of who it’s targeting: businesses that need to create a lot of training and internal videos.

But how realistic are these AI presenters when you actually use them? I put Synthesia through five tests, including creating a training video from a PDF, making an avatar of myself, dubbing a video into Spanish, and having an avatar demonstrate a warehouse safety tip. The results were really impressive in some places, but I also found a few things I’d want to fix before hitting publish.

In this Synthesia review, I’ll show you how it worked, where it impressed me, and where I think it still falls short. I’ll finish the article by comparing it to my top three alternatives: HeyGen, AI Studios, and Colossyan. By the end, you’ll know which tool is right for you!

Verdict

Synthesia is an AI video platform built mainly for training and internal communications. Its biggest strengths are fast video creation, realistic avatars, strong dubbing and localization, and easy updates. My tests also showed that its voice cloning and customizable avatars can be very convincing. However, the free plan is limited, and the videos still need a human review for things like b-roll, text layout, and action clips. Also, personal avatars also don’t perfectly capture the real person.

What is Synthesia?

Synthesia is an AI video platform that turns text into videos presented by realistic AI avatars.

It was founded in London in 2017 by Victor Riparbelli, Steffen Tjerrild, and AI researchers Lourdes Agapito and Matthias Niessner. In January 2026, it raised a $200 million Series E at a $4 billion valuation, led by GV (Google Ventures). Synthesia says it’s used by more than 90% of the Fortune 100 and has over a million users.

Those numbers tell you who Synthesia is really built for. It isn’t a creative tool for making cinematic clips. It’s a production tool for companies that need a lot of branded explainer videos, especially for training.

How Synthesia Works

In practice, a Synthesia video starts with a script. You can write it yourself, or you can describe what you want and let the AI Assistant draft the script and lay out the scenes using your brand kit. Each scene gets an avatar, a layout, on-screen text, and media, and the avatar reads its part of the script.

When you render, Synthesia generates the avatar’s speech, lip movements, and gestures. You can then export the results as an MP4, an embed, or a SCORM package for your learning platform. When a detail changes later, you edit the text and render again instead of rebooking a presenter.

The Avatars Have Moved Beyond Talking Heads

The biggest change are the avatars themselves. With the Synthesia 3.0 release in October 2025, Synthesia introduced Express-2, a model that gives avatars full-body gestures instead of just a moving face.

A month later, it added customizable avatars where you describe an outfit (“high-vis vest,” “hospital scrubs”) and a setting, then prompt a short action clip that plays right after a line is spoken. In July 2026, Synthesia announced Express-3, which it calls its most lifelike model yet, along with Dubbing 2.0.

You can also make an avatar of yourself. Upload a high-quality photo or short video, optionally clone your voice, and record a live consent statement on camera. That consent step can’t be skipped or uploaded from elsewhere, which is a meaningful safety measure for a tool that can put words in someone’s mouth.

From Videos to Conversations

Synthesia is also moving from one-way videos toward interactive ones. Videos can include clickable CTAs, branching paths, and quizzes. Roleplay Sessions (launched July 2026) let employees practice real conversations with an avatar, and the Interactive Avatar API lets companies embed real-time, lip-synced avatars in their own products.

What surprised me most was how good the core avatar videos already look. The avatars, voice clones, and lip sync were convincing enough to use in real training videos, but the surrounding details still needed a human check.

AI-generated b-roll, text layouts, runtimes, and short action clips all had issues in my tests, so Synthesia can get you most of the way there. However, I wouldn’t publish a video without watching it through first.

Who is Synthesia Best For?

Here’s who Synthesia is best for:

• Training teams can turn policies and standard procedures into short video lessons, add quizzes, share them through their learning system, and update lessons by changing the script instead of filming again.
• HR and onboarding teams can create welcome videos and benefits guides, then update them each year without booking a presenter and refilming.
• Companies with international teams can create a video once and dub it into 140+ languages instead of hiring voice talent for every market. It’s a practical AI video translation tool for teams already making videos in Synthesia.
• Product teams can create feature demonstrations and product updates with the same presenter, using customizable avatars to show the product in action.
• Customer support teams can create short how-to videos that answer common questions, which works well alongside AI customer support tools.
• Sales teams can practice handling objections with Roleplay Sessions.
• Course creators who don’t want to be on camera can present lessons with a stock avatar or their own personal avatar.
• Regulated industries (finance, healthcare, pharma) can take advantage of Synthesia’s SOC 2 Type II, ISO 42001, and GDPR compliance and its consent-based avatar creation, which make it easier to get through a security review than most competitors.
• Regulated industries like finance, healthcare, and pharma can use Synthesia’s security and privacy certifications, along with consent-based avatars, to make security reviews easier.

Synthesia Key Features

Here are the key features that stood out to me:

• AI Assistant: Turns a prompt, document, or idea into a scripted, scene-by-scene video draft that follows your brand kit.
• Stock Avatars: 240+ presenters on Enterprise (180+ on Creator, 125+ on Starter), with realistic gestures and expressions.
• Express-2 and Express-3 Avatars: Synthesia’s newest avatar models. Express-2 adds full-body movement and hand gestures, and Express-3 delivers sharper visuals and more accurate lip-sync.
• Customizable Avatars: Prompt an avatar’s outfit, setting, and action clips (B-roll) in the same editor as the talking segments (A-roll). From there, save them to your library for your team.
• Avatar Builder: Creates a realistic or stylized avatar from a prompt.
• Personal Avatars: A digital version of you, made from a photo or short video, with optional voice cloning and mandatory live consent.
• Voices & Voice Cloning: 1,000+ AI voices across 160+ languages. Express-Voice clones your voice while keeping your accent and speaking style.
• AI Dubbing: Upload an MP4, MOV, or WebM file (or paste a YouTube link) and get it back in 140+ languages with lip sync. It detects multiple speakers and clones each voice separately.
• 1-Click Translation: Translates videos made in Synthesia into 160+ languages.
• Interactivity: Clickable CTAs and branching paths available on Creator and above, quizzes exclusively on the Enterprise plan.
• Roleplay Sessions: Practice conversations with an avatar and get feedback. Self-serve plans include 10 sessions per month with 25 per month on Enterprise.
• Brand Kits & Templates: 60+ templates plus the ability to add your own brand fonts, colors, and logos to keep videos consistent.
• Live Collaboration & Version Control: Real-time co-editing (exclusively on Enterprise) and one-click updates to published videos.
• Export & Analytics: Full HD MP4, embeds, and SCORM export, plus analytics on views, drop-offs, and completion rates.
• API & Interactive Avatar API: Programmatic video generation from Creator upward, and real-time embeddable avatars for enterprises.
• API & Interactive Avatars: Create videos with the API on Creator plans and add live avatars to apps.

Hands-On Testing: What Synthesia Actually Produced

Here are the tests I ran with Synthesia. For each one, I focused on the finished video: how natural it looked and sounded, how accurate it was, and how much fixing it needed before I’d publish it.

Test 1: A Welcome Video for New Hires

For my first test, I used the AI Assistant to create an employee onboarding video from one prompt:

“Create a 90-second welcome video for new hires at a mid-size software company. Cover our three core values, where to find the employee handbook, and who to contact in the first week. Friendly but professional tone.”

I chose the “Short” length option and let the Assistant generate the video.

The video took 9 minutes to generate and came out at 56 seconds instead of the 90 I asked for in the prompt. I suspect the “Short” length setting took priority over the length in my prompt, so if you need a specific runtime, choose the length option that matches it.

My Take

The script was the best part. It sounded convincing, covered what I asked for, and nailed the friendly, professional tone from my prompt.

The avatar’s gestures and facial expressions looked authentic, and the video itself was high quality. The avatar looks very realistic, though I still think most people will be able to tell it’s AI-generated. She looks a bit too “perfect,” if that makes sense.

Synthesia also added AI-generated b-roll that made sense for the script, but this is where the video honestly fell apart. In one shot, the avatar flips open a notebook and the notebook disappears. In another, the avatar opens a laptop and it vanishes too. The b-roll’s frame rate also looked choppier than the avatar footage, which made the cuts between the two noticeable.

Overall, I’d happily use the script and the avatar segments as they are. But I’d replace or cut the b-roll clips before sharing this with new hires, because those glitches are exactly the kind of thing that makes viewers realize they’re watching AI.

Test 2: Turning an Existing Document Into a Training Video

For the next test, I uploaded a PDF of Unite.ai’s Editorial Policy to the AI Assistant and gave it this prompt:

“Turn this editorial policy into a 2-minute training video for new Unite.ai writers. Cover the most important rules they need to follow, and end with a short recap of the key points.”

I didn’t edit the outline before generating. The Assistant chose the “Dusk” style and the “Presentation” delivery style on its own. On the Starter plan, I couldn’t add a brand kit or a quiz, since those need Enterprise and Creator.

The video took 11 minutes to generate, which was 2 minutes longer than my welcome video in Test 1. It also came out at 3 minutes long, even though I asked for 2.

So in Test 1 the video was too short, and here it was too long. You can’t count on Synthesia to hit the runtime you ask for in your prompt.

My Take

The script was the highlight again. It lined up well with the editorial policy, and the text and graphics on screen were accurate to the source document. I didn’t catch it inventing any rules, which is what I was most worried about when handing it a real policy.

The avatar looked very high quality, with great facial expressions and hand gestures. But it looked a little too perfect, and I think that is exactly what will make viewers realize it’s AI. The lip movements were accurate, but they looked a bit overemphasized, as if the avatar was over-enunciating every word.

The biggest visual flaw was the text layout. In one scene, the “g” at the end of “Advertising” wrapped onto its own line, which looked sloppy. It’s a quick fix in the editor, but it’s the kind of mistake you’d need to catch before sharing the video.

Overall, this video was a more usable result than Test 1. I’d trust the content, but I’d still watch the video from start to finish to catch layout issues, and I’d trim it to get closer to the length I actually wanted.

Test 3: Creating a Personal Avatar of Myself

Next, I created a personal avatar of myself from a photo, with a voice clone and Synthesia’s mandatory live consent recording. Synthesia also asked me to describe my outfit and surroundings, so I described what I was actually wearing and the room I was in to keep the comparison fair.

Then I had my avatar read a short paragraph I’d never recorded, and filmed myself reading the same paragraph so I could compare the two side by side.

Here’s the real me:

And here’s my Synthesia avatar reading the same paragraph:

My Take

On its own, the avatar looks authentic and high quality. But next to the real me, it doesn’t actually look like me.

I felt like the biggest physical difference was my mouth. It just didn’t move or look like my actual mouth, and I felt like the avatar’s mannerisms didn’t capture my personality. The avatar comes across as much more excited than I am in real life.

That matches what I noticed in Test 2, where the stock avatar’s lip movements looked overemphasized. Synthesia’s avatars seem to default to an exaggerated, upbeat delivery.

However, the voice clone was the part I felt that worked most effectively. It genuinely sounded like me.

But in all honesty, I found the whole thing pretty creepy. Either way, I wouldn’t use this avatar in place of myself on camera. The voice clone is convincing enough, but the face and expressions aren’t close enough to pass as me, especially for anyone who knows me.

Test 4: Dubbing a Real Video Into Spanish

For test 4, I used Synthesia’s AI Dubbing to translate an English talking-head video of myself into Spanish. It’s the same video I dubbed in my ElevenLabs review, so I could compare the two tools directly.

Here’s the original English video:

Here’s Synthesia’s Spanish dub:

And here’s the ElevenLabs version for comparison:

Dubbing took 14 minutes on Synthesia, which was longer than I expected for a video this short. It used 287 of my 800 monthly credits, so one short dub cost me over a third of my allowance.

My Take

The lip sync genuinely impressed me. My mouth movements matched the Spanish audio closely, and even the teeth looked right. There was a bit of glitching, but overall it looked real.

This is where Synthesia clearly beat ElevenLabs. ElevenLabs dubbed my video successfully, but it only replaced the audio, with no lip sync, so my mouth was still making English shapes under Spanish words. Synthesia actually changed how my mouth moves to match the new language, which makes a huge difference to how believable the result is.

But with that said, it still creeped me out a little. My mouth moved in ways I don’t move it when I speak in real life, which is the same issue I had with my personal avatar in Test 3.

Also, the voice was weaker. It sounded a bit too high-pitched, though it wasn’t bad. To me, ElevenLabs’ Spanish voice sounded more like my actual voice.

So if I were dubbing a video for viewers who will actually watch my face, I’d choose Synthesia for the lip sync. If it were audio-based content (like a podcast clip or a voiceover), my pick would be ElevenLabs.

Test 5: A Customizable Avatar Demonstrating a Safety Tip

For my final test, I wanted to see whether Synthesia’s customizable avatars could handle something closer to real training footage. I wrote a short warehouse safety tip about lifting boxes properly and imported it as my own script.

From there, I customized a stock avatar by prompting her outfit (a high-visibility vest and hard hat) and her setting (a warehouse aisle). I also generated an action clip of her lifting a box with proper form, to play while the narration explains the technique. Synthesia’s prompt-based action clips are generated with Google’s Veo 3 model.

The video took 7 minutes to generate.

My Take

This was my favorite result of all my tests. The outfit and warehouse setting came out exactly as I’d pictured them, and the avatar looked incredibly realistic and high quality. She also looked identical in the talking scenes and the action clip.

The box lift was believable, too. There were no warping hands, the box didn’t disappear (unlike the notebook and laptop in Test 1), and her lifting form was correct, which matters a lot in a safety video.

My frustrations were with the editing, not the output.

The action clip was only four seconds long, shorter than the line narrating it. So Synthesia looped it once, and that part of the video looks a bit choppy. I couldn’t avoid this by letting the clip play on its own, because every scene in Synthesia needs a script. There’s no blank scene either, so I had to add a template scene and delete everything on it to give the clip its own slide.

But even with that loop, I can totally see this being used for actual safety training. If you’re making one, do your best to match the narration length to the action clip so it only plays once.

Results & Output Quality

Here’s what I noticed across my tests:

• Realism: The avatars looked very realistic, with authentic gestures and expressions. However, they were a bit too perfect and overemphasized lip movements still give them away as AI.
• Voice quality: Scripts sounded convincing and my voice clone genuinely sounded like me. However, it sounded like my Spanish dub came out higher-pitched than my actual voice.
• Accuracy: The AI Assistant nailed the tone I asked for and stayed faithful to the editorial policy I uploaded, with no invented rules that I could spot.
• Consistency: My customized avatar looked identical in the talking scenes and the action clip. However, my runtimes weren’t consistent at all (56 seconds when I asked for 90, then 3 minutes when I asked for 2).
• Speed: Every render took between 7 and 14 minutes, even for videos under a minute long.
• Editing required: My safety video (Test 5) was usable as-is despite one looping clip. However, I’d have to cut the glitchy b-roll from Test 1, and fix a broken text wrap and trim the length in Test 2.
• Credits used vs. output: Dubbing one short video used 287 of my 800 monthly credits on Starter, so the allowance goes quickly once you add dubbing.
• Where it fell short: I felt that the custom avatar of myself didn’t capture my real face or personality. Also, automatic b-roll and short, looping action clips made parts of the videos look choppy.

How to Get Good Results in Synthesia

Here’s the workflow that I found produces the most usable videos:

1. Start from a tight script, not a vague prompt. The AI Assistant can draft a video from an idea, but giving it your actual source material (a policy, an SOP, or a product page) keeps it from filling gaps with generic filler.
2. Set up your brand kit first. Fonts, colors, and logos applied at the start save you from restyling every scene manually later.
3. Write for the ear. Short sentences and clear punctuation give the avatar better pacing. Spell out acronyms and write brand names phonetically if the voice mispronounces them. Better yet, set a pronunciation by highlighting the word in the script editor. Select Pronunciation to adjust how it sounds, and type a phonetic spelling manually or record yourself saying the word, which the system will turn into a phonetic spelling.
4. Keep scenes short. One idea per scene makes it easier to match gestures and on-screen text, and makes future edits easier.
5. Preview before you render. Every full render uses minutes from your monthly allowance, so check the script and timing first.

Top 3 Synthesia Alternatives

Here are the best Synthesia alternatives I’ve tried that I’d recommend.

HeyGen

HeyGen is Synthesia’s closest rival, and the choice mostly comes down to who the videos are for.

On the one hand, HeyGen leans toward creators and marketers. Its free plan gives you 500+ stock avatars and a custom avatar (compared to Synthesia’s 9 free avatars). 4K video export starts on Pro, and it supports 175+ languages starting on the Creator plan.

Meanwhile, Synthesia is built around corporate training. It includes branching and API access on the Creator plan, while HeyGen keeps interactive video and SCORM for its Business plan.

Choose HeyGen if you’re making marketing or social videos. Otherwise, choose Synthesia if you’re building training content for an LMS.

Read my HeyGen review or visit HeyGen!

AI Studios

AI Studios (from DeepBrain AI) is the alternative I’d point budget-conscious teams to, because it doesn’t ration minutes the way Synthesia does.

On the one hand, AI Studios’ Personal plan includes unlimited videos up to 30 minutes each, 3 custom avatars, 1080p export, and 120 minutes of AI dubbing a month. Synthesia’s Starter plan caps you at 10 minutes of video. The AI Studios Team plan adds 4K video exports.

Meanwhile, Synthesia offers the more complete training package: interactive quizzes and branching, Roleplay Sessions, a larger avatar library, and 140+ dubbing languages, compared with 73 languages and dialects for AI Studios. AI Studios sells interactive avatars as a separate plan.

Choose AI Studios if you produce a lot of videos and want more minutes for your money. Otherwise, choose Synthesia if interactivity and localization matter more than volume.

Read my DeepBrain AI review or visit AI Studios!

Colossyan

Colossyan targets the same buyer as Synthesia (training teams), so this comparison is about features for the price rather than audience.

On the one hand, Colossyan puts more of its training features on lower tiers. Its free plan includes 20 minutes a month and 10 interactive videos.

The Professional plan adds SCORM export (5 a month), 15 interactive videos, and up to 3 editors. To get branching, you need the Creator plan while quizzes are on Enterprise in Synthesia.

Meanwhile, Synthesia has more voices and languages (160+ versus 100+). It’s also the more established choice for enterprise security reviews.

Choose Colossyan if you’re a small training team that needs interactive courses on a tighter budget. Otherwise, choose Synthesia if avatar realism, localization, and scale are the priority.

Read my Colossyan review or visit Colossyan!

Synthesia Review: The Right Tool For You?

What I liked most about Synthesia is how easily it turns a script into a professional video without a camera or real-life presenter. In my tests, the scripts were strong, the stock avatars looked realistic, and the customizable avatar produced my favorite video.

What I didn’t like was the cleanup. The AI generated b-roll I generated looked choppier than the talking head, text needed fixing, and video lengths didn’t always match what I requested. My personal avatar also looked realistic but didn’t look enough like me to replace me on camera.

I’d recommend Synthesia to training and HR teams that need to make professional videos regularly, especially in multiple languages. But for occasional video creation, the monthly limits may be harder to justify and you might want to consider these alternatives:

• HeyGen is best for marketers and creators who want 4K output and lots of stock avatars.
• AI Studios is best for high-volume production with unlimited videos on its Personal plan.
• Colossyan is best for small training teams that want interactive SCORM training for less.

Thanks for reading my Synthesia review! I hope you found it helpful. If you want to try Synthesia for yourself, you can sign up for free and see what it can build for you.

Frequently Asked Questions

Is Synthesia free?

Yes, Synthesia has a free Basic plan with no credit card required. It includes 10 minutes of video and 10 minutes of dubbing a month, and 9 avatars.

How realistic are Synthesia’s avatars?

Synthesia’s avatars look very realistic. But in my testing, the slightly exaggerated mouth movements and facial expressions still made them look AI generated, and my personal avatar didn’t capture my real face or mannerisms closely enough to pass as me.

Can I make an AI avatar of myself with Synthesia?

Yes, you can create a personal avatar from a photo or short video, with an optional voice clone. You’ll need to record an on-camera consent statement, which can’t be skipped or pre-recorded. Starter includes 3 personal avatars, Creator includes 5, and Enterprise is unlimited.

How many languages does Synthesia support?

Synthesia supports 160+ languages and voices for creating videos and 140+ languages for AI dubbing.

Can Synthesia dub an existing video?

Yes, Synthesia can dub an existing video. You upload an MP4, MOV, or WebM file (up to 4K) or paste a YouTube link, and it returns a lip-synced version in another language with the speaker’s cloned voice. You can then correct any translated line in the editor.

Can I use Synthesia videos commercially?

Yes, you can use Synthesia video commercially. It’s made for business use, including training, marketing, and sales videos.

Does Synthesia work with my LMS?

Yes, Synthesia exports videos as SCORM packages, so they can be uploaded to most learning management systems. Just keep in mind that SCORM export is exclusively available on the Synthesia Enterprise plan.

Is Synthesia safe to use?

Yes, Synthesia is SOC 2 Type II, ISO 42001, and GDPR compliant. Plus, it requires live consent before creating a personal avatar.

Is Synthesia worth it?

Synthesia is worth it if your team regularly produces training videos (especially in several languages), and needs reliable security. If you only need a few short videos, the monthly minute caps may make HeyGen or AI Studios better value.