[2025 Latest] 10 Recommended AI Speech Synthesis Software! A Thorough Comparison of Free and Paid Software
July 11, 2025
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AI speech synthesis software that converts text into natural-sounding speech is currently attracting attention.
Advances in AI technology have dramatically improved the quality of speech synthesis software.
It can generate natural, human-like speech with a quality that is incomparable to the old mechanical reading systems.
What's more, even free speech synthesis software can synthesize speech at professional-quality levels .
The applications of speech synthesis software are rapidly expanding, including narration for video production, creating language learning materials, and business presentation materials .
In this article, we will introduce a carefully selected list of the latest recommended voice synthesis software for 2025!
We will explain in detail the features and usage of each software, from free software to paid software, so why not find the voice synthesis software that's perfect for you?
[Free] Recommended AI speech synthesis software you can use right away
If you're looking for voice synthesis software, we recommend "Ondoku" !
"Ondoku" is a voice synthesis software that uses the latest AI technology and can be used for free from your browser.
No installation is required, so you can easily create high-quality voice synthesis right away.
It's free , can read out up to 5,000 characters, and can even be used for commercial purposes!
It supports multiple languages, including not only Japanese but also English, Chinese, and Korean, so you can easily create audio in foreign languages.
If you're not sure which speech synthesis software to choose, why not try "Ondoku" for free first?
What is Text-to-Speech Software? Basic Knowledge Explained for Beginners
First, let me give you a brief explanation of voice synthesis software.
What are the features of speech synthesis software that has evolved with AI technology?
Text-to-speech software is software that automatically converts input text into speech .
In fact, this software is gaining more and more attention and more and more people are using it .
Previous voice synthesis software produced a mechanical, unnatural sound.
But now, with the latest AI technology , it is possible to speak with natural intonation and pauses like a human.
In particular, voice synthesis software that utilizes deep learning makes it possible to produce realistic, easy-to-understand expressions like those of professional voice actors and narrators.
You can also make detailed customizations, such as adjusting the reading speed and changing the pitch of the voice.
Types of speech synthesis software [AI web apps are recommended!]
There are two main types of speech synthesis software.
There are two types of speech synthesis software: web app type that can be used from a browser, and desktop type that can be installed on a computer.
The appeal of web-based speech synthesis software that can be used from a browser is that it requires no installation and can be used immediately.
With the AI web app "Ondoku," you can take advantage of the latest AI technology regardless of the performance of your PC.
Installed speech synthesis software has the advantage of being able to be used in offline environments.
It is recommended that you choose which speech synthesis software based on your usage environment and purpose.
Top 10 Best Speech Synthesis Software for 2025 (Free and Included)
Now, let's take a closer look at the latest recommended voice synthesis software for 2025!
"Ondoku" | Free speech synthesis software that uses the latest AI
"Ondoku" is a high-quality voice synthesis software that uses the latest AI technology .
If you're looking for text-to-speech software, this is your first choice !
It is a web application software that can be used from a browser, and does not require any complicated installation work.
Simply enter text and press a button to synthesize a natural-sounding audio file in just a few seconds .
There are 16 different Japanese voices to choose from, including a wide variety of female, male, and child voices .
It supports multiple languages , making it easy to synthesize voices in foreign languages such as English, Chinese, and Korean.
You can freely adjust the reading speed and pitch to create the optimal voice for your needs.
Commercial use is also allowed, making it ideal for YouTube monetization and business use .
What's more, "Ondoku" is free!
Since you can use it without registering or logging in , we recommend that you first try out voice synthesis using the latest AI.
Why not try out "Ondoku" for free ?
VOICEVOX | Voice synthesis software that lets you use popular characters like Zundamon
VOICEVOX is a desktop speech synthesis software that is compatible with Windows, Mac, and Linux.
The biggest feature is that it can be read aloud in the voices of popular characters such as "Zundamon," "Shikoku Metan," and "Kasukabe Tsumugi."
It uses deep learning technology and allows for fine-tuning of the audio.
The software itself is free and can be used for commercial purposes, but please note that the terms of use vary for each character.
A GPU-compatible version is also available, allowing for faster processing on high-performance PCs.
Boyomi-chan | Voice synthesis software for streaming
Boyomi-chan is a voice synthesis software that is widely used in game streaming and live streaming .
It can synthesize speech using a distinctive voice known as "Yukkuri Voice."
It also has a wide range of integration functions with streaming software such as OBS , making it ideal for reading out comments.
It is also commonly used in "Yukkuri Commentary" and "Yukkuri Commentary" on Nico Nico Douga and YouTube.
This is lightweight free software for Windows that runs smoothly even on low-spec PCs.
Since it uses an older version of AquesTalk, it can be used for commercial purposes even if it is free.
Although the sound quality is mechanical, this speech synthesis software is loved by many creators for its unique personality.
SofTalk | A simple voice synthesis software with a long history
SofTalk is a simple, free speech synthesis software for Windows .
It has a simple interface that focuses on basic functions , making it easy to use even for beginners.
You can choose from multiple speech synthesis engines, so you can choose the voice that best suits your needs.
*Previously, it supported "Yukkuri Voice", but it is no longer supported.
The software itself is free, but if you plan to use it for commercial purposes, you will need to check the terms and conditions of the voice engine you use.
This is free software that is ideal for those looking for basic speech synthesis functions.
COEIROINK | AI voice synthesis software for creative activities
COEIROINK is an AI voice synthesis software developed for creative activities .
It is a desktop version that is compatible with Windows, Mac, and Linux, and can read aloud using a variety of character voices.
In addition to official and authorized characters, the user-created voice model "MYCOE" can also be used.
Commercial use is permitted, but credit is required .
Also, since the terms of use differ for each voice model, it is important to check before use.
This is a speech synthesis software suitable for those who want unique voices for creative purposes.
TextTalk | Lightweight speech synthesis software for Windows
TextTalk is a lightweight, simple, and free text-to-speech software for Windows .
It uses OpenJTalk and the standard Windows speech synthesis engine.
Compared to the latest AI, there are limitations to the naturalness of the voice, but it is sufficient for basic reading.
This software can be used simply by unzipping the ZIP file, and can be used comfortably even on older PCs or in low-spec environments.
Yukumo! | Speech synthesis software that lets you use Yukkuri Voice from your browser
Yukumo! is a web application type speech synthesis software that allows you to use "Yukkuri Voice" from your browser.
No installation required and can be used on any device.
It supports multiple versions including AquesTalk1, AquesTalk2, and AquesTalk10.
This is a voice synthesis software recommended for those who want to start using "Yukkuri Commentary" or "Yukkuri Live Commentary" without the need for installation.
AIVOICE | Paid voice synthesis software compatible with popular VOICEROID characters
AIVOICE is a high-quality paid voice synthesis software developed by AI Corporation.
AIVOICE2 is the successor to VOICEROID and is currently available .
The biggest feature is that it includes a lineup of popular character voices such as "Yuzuki Yukari" and "Kotoha Akane/Aoi."
It is compatible with both Windows and Mac and is sold as a one-time paid speech synthesis software.
Personal commercial use is generally possible with product purchase, but corporate use requires a separate license.
This is a voice synthesis software that is ideal for creating creative audio works and high-quality narration.
CeVIO | Paid voice synthesis software with rich expressions that use popular characters
CeVIO is a speech synthesis software that combines reading and singing functions.
It is sold as a one-time paid speech synthesis software exclusively for Windows .
It features the unique voices of popular characters such as "Sato Sasara" and "Suzuki Tsuzumi."
Our unique speech synthesis AI can read text aloud with rich emotion.
In addition to the "talk voice" for reading aloud, there is also a "song voice" for singing, so it supports both reading aloud and singing.
The commercial use conditions for individual creators are relatively lenient, but a separate license is required for corporate use.
This is a speech synthesis software recommended for those who want to create audio content with rich expressiveness.
VOICEPEAK | Paid voice synthesis software with a wide variety of characters
VOICEPEAK is one of the few desktop speech synthesis software that is compatible with Windows, Mac, and Linux.
This also allows voice synthesis using a variety of popular characters.
Another feature is that some packages come with multiple character voices .
The basic license includes commercial use rights, but separate terms apply to character voices.
Perfect for voiceover production and multi-platform voice synthesis.
How to use voice synthesis software? A detailed explanation of how to use "Ondoku"

From here, we will explain how to actually use voice synthesis software, using "Ondoku" as an example!
[Free] How to read text aloud using the speech synthesis software "Ondoku"
If you are planning to use speech synthesis software, we recommend a web app-based speech synthesis software that is easy to use and does not require installation !
To have Ondoku read text aloud, first visit the official website .
When you open the top page, there is a text box where you can enter the content you want to read out loud .
(Copy and paste is OK)
Next, select the voice type.
You can listen to the audio that can be used with "Ondoku" in this article, so please take a look!
All you have to do is click or tap the "Read aloud" button !
High-quality audio is completed in just a few seconds .
The audio file can be downloaded in MP3 format , so it can be used for a variety of purposes, such as video narration or in-store announcements.
As you can see, the free voice synthesis software "Ondoku" is very easy to use.
If you're looking for voice synthesis software, why not start with "Ondoku" ?
Ondoku allows you to adjust the reading speed and pitch.
The speech synthesis software "Ondoku" also supports adjusting the reading speed and pitch !
It is effective to adjust the reading speed depending on the importance of the content.
When using it to study a language, it is recommended to drastically slow down the speed all at once.
When using it for video narration, we also recommend adjusting the audio pitch.
By changing the height, you can create a character that suits the listener.
What are the advantages and disadvantages of AI voice synthesis software?
When using speech synthesis software, it is recommended that you fully understand the advantages and disadvantages.
We will briefly explain the advantages and disadvantages of AI voice synthesis software.
What are the benefits of AI voice synthesis software?
The biggest advantage of speech synthesis software is that it reduces costs .
If you hire a professional narrator, you will incur many expenses, including recording fees, studio fees, and travel expenses.
You can significantly reduce these costs by choosing speech synthesis software that is free for commercial use.
One of the major benefits is that it reduces the time it takes to create audio .
Until now, creating video narration or in-store announcements required a lot of time, including scheduling recordings, reshooting, and editing .
However, with speech synthesis software, you can simply enter text and have the speech generated in just a few seconds .
Create high-quality audio anytime, for free
Another advantage of AI speech synthesis software is the high quality of the audio.
When a human reads the text aloud, the quality can vary depending on their physical condition and mood .
Also, if you record yourself without hiring a professional, the audio may end up being very difficult to hear.
On the other hand, speech synthesis software can generate speech of the same quality every time .
There is no need to worry about the sound quality being affected by recording equipment or the surrounding environment.
Another advantage of speech synthesis software is that it can be used 24 hours a day, 365 days a year .
You can create audio instantly whenever you want, even late at night or early in the morning .
With multilingual speech synthesis software, you can easily create narration in foreign languages.
Disadvantages of AI voice synthesis software
Text-to-speech software also has some drawbacks.
Depending on the software, there may be limitations to the emotional expression.
If you are not satisfied with the expression, we recommend trying out free voice synthesis software that uses the latest AI .
Caution is also required for commercial use .
Some paid software has restrictions on commercial use, so be sure to check the terms of use beforehand.
If you want to monetize your videos or use them for business purposes, free software that can be used for commercial purposes, such as "Ondoku," is ideal.
[Free] How to get the most out of speech synthesis software? Explaining how to use it for different purposes
Finally, we will explain in detail how to use voice synthesis software for different purposes!
Video production/YouTube narration
If you want to add narration to your video production, voice synthesis software is the best option.
When using speech synthesis software for video production, it is important to use software that can read in a natural, unobtrusive voice.
Another important point is to choose commercially available speech synthesis software that supports monetization on YouTube and other platforms.
Ondoku 's high-performance AI speech synthesis engine allows you to create easy-to-listen voices that sound like professional narrators.
An important thing to remember when producing videos is to adjust the reading speed according to the content .
It is effective to set the important parts a little slower.
Create language learning materials for free
Free speech synthesis software is also recommended for practicing pronunciation when learning a language .
By using "Ondoku," which supports multiple languages , you can accurately study the pronunciation of various languages.
Creating materials for shadowing , an effective language learning technique, is easy with speech synthesis software.
It is also recommended for improving your foreign language listening skills.
The key point when creating language learning materials is to start with a slow playback speed.
Ondoku allows you to slow down the playback speed to 0.3x , making it ideal for those just starting to learn a foreign language.
Using speech synthesis software for business purposes
Of course, speech synthesis software can also be used for business purposes in companies .
- Audio conversion of presentation materials
- Add audio to your in-house training materials
- Call center voice guidance
- Announcements within the facility
Speech synthesis software can be used for a wide range of purposes, such as:
For companies that prioritize security , the Japanese service "Ondoku" is a safe choice.
Even if you are using it for business purposes, be sure to use speech synthesis software that is compatible with commercial use.
Game streaming/live streaming
When using speech synthesis software for live streaming , real-time reading is important.
By linking streaming-specific voice synthesis software like Boyomi-chan with OBS, you can check comments without taking your eyes off the screen.
You can also make your broadcast even more exciting by using the viewer comment reading function.
Improved accessibility
Text-to-speech software is also an extremely important tool for people with visual impairments and learning disabilities.
By converting text on websites into audio , digital information becomes more accessible to a wider audience.
Introducing speech synthesis software can improve usability not only for people with disabilities but also for services aimed at the elderly.
When creating audio that is easy for everyone to understand, it is important to use AI speech synthesis software that produces natural voices .
High-quality AI speech synthesis software with realistic voices can create speech that is easy to listen to for long periods of time without tiring you out.
If you are making your company or organization's website accessible or creating announcements for public facilities , we recommend the latest AI speech synthesis software.
Why not try out the voice synthesis software that's best for you?
Advances in AI technology have made it possible for anyone to easily create high-quality voice using speech synthesis software.
Even free software can produce professional-level speech synthesis .
The important thing is to choose the best speech synthesis software for your purpose, whether it's video production, language learning, or business.
If you are considering commercial use, such as monetizing YouTube, it is important to carefully check the terms of use and use speech synthesis software that allows commercial use .
For beginners, we recommend starting with an easy-to-use web-based speech synthesis software.
With "Ondoku," you can easily experience voice synthesis right now, for free and without installation .
The possibilities of speech synthesis software are endless.
Why not try out some free voice synthesis software first?
■ AI voice synthesis software "Ondoku"
"Ondoku" is an online text-to-speech tool that can be used with no initial costs.
- Supports approximately 50 languages, including Japanese, English, Chinese, Korean, Spanish, French, and German
- Available from both PC and smartphone
- Suitable for business, education, entertainment, etc.
- No installation required, can be used immediately from your browser
- Supports reading from images
To use it, simply enter text or upload a file on the site. A natural-sounding audio file will be generated within seconds. You can use voice synthesis up to 5,000 characters for free, so please give it a try.
Email: ondoku3.com@gmail.com
"Ondoku" is a Text-to-Speech service that anyone can use for free without installation. If you register for free, you can get up to 5000 characters for free each month. Register now for free