My Hands-On Review of Synthesia vs. HeyGen: Here’s the Winner

When I first explored AI video generators, I consistently came across two names: Synthesia and HeyGen. It was hard to ignore them, given their emerging popularity in crafting videos with lifelike virtual presenters.

Both platforms take text-to-speech and avatar technology to the next level, allowing users to create polished videos from scripts. However, as I delved deeper, it became clear that they cater to different audiences.

Synthesia, founded in 2017, is often the go-to choice for corporate training and multilingual internal communications. On the other hand, HeyGen has carved out a niche for itself among small businesses and content creators seeking hyper-realistic avatars. HeyGen was recently recognized as G2’s #1 Fastest Growing Product of 2025.

User ratings on G2 are telling. Synthesia holds a solid average of 4.7 out of 5 across around 2,376 reviews, while HeyGen takes a slight lead with 4.8 out of 5 from about 1194 reviews.

In this article, I’ll dive deep into the features, performance, and user experiences of both platforms to help you decide which AI video generator might be the best fit for your needs.

• AI avatars: Synthesia’s pre-made avatars provide enterprises with numerous on-brand presenter options, whereas HeyGen’s focus has been on making user-generated avatars easy to create. You can record a short video of yourself, and HeyGen will create a personalized avatar from it.
• Languages and voice technology: HeyGen supports 175+ languages and dialects, slightly more than Synthesia’s 140+ language palette. Each offers many accents and voices. Users can simply select a language and an AI voice, and the avatar will speak the script. HeyGen allows you to create a clone of your own voice from a sample. Synthesia has historically not offered self-service voice cloning, although it does allow users to upload their own recorded audio for an avatar to lip-sync.
• Editing interface: Synthesia’s interface is like a slide deck editor (similar to Google Slides). You build the video scene by scene, using text boxes, images, and the avatar, with dozens of business-oriented templates. HeyGen also utilizes a scene-based editor, but it comes with a larger library of creative templates and a richer built-in asset library. In terms of advanced features, Synthesia has introduced interactive video elements and provides an API for enterprise automation, reflecting its enterprise focus. HeyGen’s focus has been on rapid content creation; for instance, its new video agent AI generates videos from a prompt or URL, and it emphasizes ease of use over heavy integration.
• Performance and scalability: HeyGen is frequently praised for its speed. Users report that it generates videos and even revisions very fast, saving hours in content production. Synthesia is also generally fast, but some users have observed that at peak times (if many jobs are in the queue), rendering can slow down a bit. 

Synthesia vs. HeyGen: What’s similar?

Here are some similarities between the two AI video generator platforms: 

• Stock avatars + custom avatars: Each offers a sizeable built-in avatar library and the option to create a personal/custom avatar. These cover common business personas such as presenters, trainers, sales reps, and product explainers.
• Multilingual voices and dubbing: Both support broad language coverage for narration and localization, enabling global content. It enables fast localization workflows and maintains visual consistency when changing narration across regions.
• Browser-based editors with templates: Both provide web editors and ready-made templates for business and marketing use cases. This lowers the learning curve and shortens time-to-value. Teams move from script to finished video in minutes, not days.
• HD exports and standard formats: Both plans offer downloadable HD videos (MP4) on paid tiers; free tiers are available with usage/quality limits. It makes free plans suitable for testing, not production. For serious business use, HD exports on paid tiers are table stakes, and both platforms meet that expectation.

The Synthesia interface is well-suited for corporate training use cases and is easier to work with for individuals who frequently give presentations. I found HeyGen to be better suited for sales and marketing-related use cases that are already familiar with conversational AI to some extent, and want to keep a casual and friendly tone. 

Avatar realism

In the video editor, Synthesia offers a variety of avatars for you to choose from. While there are a few options available on the free plan, some would require you to upgrade to the paid version.. The avatars look realistic but have a more formal tone. On Synthesia, you have the option to personalize your avatar with custom outfits. 

HeyGen also gives you a wide range of avatars to choose from. I found its avatars to be modern and realistic. There are different angles of the same avatar that you can use based on what fits your content delivery the best. 

I felt HeyGen has better avatar realism compared to Synthesia. Alternatively, it may be a bias because Synthesia uses more corporate avatars, which are similar to those found in stock images. 

Winner: HeyGen, since it has more realistic avatars compared to Synthesia. 

Voice quality and options 

Voice quality is based on the avatar you choose. In Synthesia, you have different voice options tied to different speakers, but when you change, it changes the avatar, too. The voice quality is decent and has a somewhat professional tone. 

HeyGen gives you options to customize the voice in your video. You can listen to different audio, just like on Instagram, and choose the voice you like the most. When you choose the voice, it doesn’t change the avatar. In HeyGen, choosing voice options is easier, as it provides context about the voices (formal, young, middle-aged, etc.). It becomes easier to make a choice. 

Winner: HeyGen, because it’s easier to choose the best-fit voice for the video. 

Editing flexibility

You’ll find Synthesia to be more flexible if you have worked with presentations and slideshows. You have the option to customize the layout, background, avatar, text, and various components of the video individually. Although it may take some getting used to at first, once you’re hands-on, editing these videos becomes a lot easier.

You can add different types of components, such as interactive elements on the video, to make it more engaging. It’s a sought-after feature for creating training videos to increase audience participation and engagement. 

Similarly, HeyGen also offers a wide range of editing options. The editing studio offers you the flexibility to customize various elements in your video. Most importantly, it provides an AI option to describe the changes you need in the video and allows you to make them seamlessly. 

On HeyGen, you’ll feel like you’re editing a video just like you do on Instagram or Facebook. 

Winner: Tie. Both platforms offer a range of customization and editing options. Based on the use case, they’ll deliver reliable editing flexibility. 

Output quality and formats

Both Synthesia and HeyGen generate videos in MP4 format with a reliably clear output.

When asked to download in MP4, Synthesia prompts to upgrade to a paid plan. However, you can create a link to share the video with others, which is available in the free plan.

HeyGen stands out here as it lets you download MP4 videos in 720p, which is a decent quality, on the free plan. If you require 1080p or 4K video quality, the platform will require you to upgrade to a paid plan. HeyGen also lets you create a shareable link that you can use to distribute your content. It also provides the option to generate an embed code, allowing you to integrate your video content into a webpage.

Winner: HeyGen, because it offers the ability to download videos of decent quality without requiring a switch to a paid plan.

Here’s a quick overview of our comparison between Synthesia and HeyGen:

Both Synthesia and HeyGen offer impressive AI video generation capabilities, but they cater to different needs. If you require a tool for corporate training and polished presentations, Synthesia’s extensive features and avatar library make it a strong choice.

Conversely, for those looking for hyper-realistic avatars and creative flexibility, HeyGen stands out. Ultimately, your choice will depend on your specific use case.

Ready to dive into the world of AI video generation? Discover the top AI video generation platforms curated by an expert on G2.