How to Create AI Podcasts | Automatically Generate Audio Content from Text

I want to turn my blog posts into a podcast, but I don't have a microphone or editing skills...

Have you ever thought about distributing the content of your blogs or documents as audio via a podcast?

Nowadays, by using AI tools, you can create a podcast simply by inputting text.

In this article, we will compare five tools that can create AI podcasts from text and explain the specific steps to create them.

What you will learn in this article:

• Features and differences of 5 tools for creating AI podcasts from text
• How to choose the recommended tool according to your purpose
• Specific steps for converting blog posts into podcasts
• Tips for improving the quality of AI voice podcasts

5 AI Tools to Create Podcasts from Text

Tools that generate audio content through AI simply by entering text or an article URL are appearing one after another.

Here, we introduce five recommended AI podcast generation tools that can be used in Japanese.

1. Ondoku: The top choice for voice flexibility and commercial use

"Ondoku" is a text-to-speech service that generates high-quality AI voice simply by inputting text.

Since the generated audio can be downloaded as an MP3 file, it can be used directly as the audio source for a podcast.

The biggest attraction is the ability to read aloud in a wide variety of voices supporting multiple languages.

Since reading speed and pitch can be adjusted in detail, you can finish with audio that perfectly matches the content and atmosphere of your podcast.

Furthermore, because commercial use is OK, you can use it with peace of mind even when you want to monetize your podcast.

By using the Conversation feature, you can also manually create content in a dialogue format by switching between two voices.

This tool is ideal for people who want to create narration-style podcasts or those who are particular about voice customization.

2. Google NotebookLM: Automatically generate dialogue-style podcasts just by entering a URL

Google NotebookLM is a tool that automatically generates a podcast where two AI hosts explain content in a dialogue format just by inputting a URL or PDF.

It has supported Japanese since April 2025 and can be used for free.

Operation is simple: just add the source (URL or PDF) and click "Generate audio overview."

While its ease of use is attractive, voice types are limited, and detailed adjustment of reading speed or tone is not possible.

Note that you cannot have it read aloud text that you have written exactly as it is.

Since the content automatically summarized by the AI is read aloud, if you want to create the content you want to convey yourself, a tool that can read text exactly as it is is recommended.

3. castmake: An AI radio generation service optimized for Japanese

castmake is a service from Japan that can generate AI radio in about 3 minutes just by inputting the URL of a blog post.

A feature is that it can introduce the content of up to five articles from a single URL, allowing you to easily create content like a digest program that summarizes multiple articles.

It also supports RSS distribution to Apple Podcast and Spotify, so everything from generation to distribution is completed in one stop.

This service is perfect for people who want to turn Japanese content into audio in a dialogue format.

However, detailed adjustment of voice types and tones is not possible.

4. ElevenLabs GenFM: Generate podcasts with high-quality AI voices

ElevenLabs is a service known for high-quality AI voice synthesis.

Using the podcast generation feature "GenFM," you can automatically create dialogue-style podcasts from text, PDFs, or URLs.

It supports 32 languages, and a feature is that the generated script can be edited later.

You can also fine-tune the content generated by the AI yourself.

While the voice quality is top-class, a paid plan (from $5 per month) is required.

However, the operation screen is in English only. It does not support Japanese for the UI.

5. Monica AI: A free AI podcast generation tool

Monica AI is a free AI podcast generation tool that supports various formats such as text, PDF, and URL.

When you input content, the AI automatically converts it into podcast-format audio.

This tool is recommended for those who want to try an AI podcast for free first.

Comparison of AI Podcast Generation Tools

We will compare the five podcast creation tools introduced so far.

How to Choose an AI Podcast Tool by Purpose

We have introduced five tools, but many people might wonder, "Which one is actually best?"

The key point when deciding which tool to use is what kind of podcast you want to create.

When you want to easily create high-quality podcast audio

For those who want to "turn their own blog into a podcast with pleasant narration audio," "Ondoku" is recommended.

Since you can choose a voice that matches the atmosphere of the program from over 650 voices, you can use them differently—for example, an adult woman's voice for a calm commentary program, or a bright tone for a casual program.

In addition to adjusting speed and pitch, you can also specify tone and reading style, so it can respond to detailed requests like "I want you to read a little slower and more gently."

Since the generated audio can be downloaded as an MP3, you can create a professional podcast just by layering background music afterward.

When you want to easily create dialogue-style podcasts

If you want to "create a podcast like a radio show where two hosts explain while conversing," NotebookLM or castmake are convenient.

Both can automatically generate dialogue-style podcasts with AI just by inputting a URL or text.

NotebookLM is provided by Google and is attractive because it can be used for free.

castmake is a service from Japan, so it has good compatibility with Japanese content and supports distribution to Apple Podcast and Spotify.

When you want to "pursue higher audio quality" or "manually revise the generated script," ElevenLabs' GenFM is also recommended.

Explaining How to Create a Podcast with Ondoku

From here, we will introduce the steps to create a podcast from a blog article using "Ondoku".

First, format the blog article text into spoken language.

Since reading written language as it is gives a stiff impression, it is easy if you ask ChatGPT to "convert this text into spoken language for a podcast."

Next, open the "Ondoku" page.

This time, we will create audio using "Ondoku Beta", which can read aloud with more realistic and easy-to-hear voices.

Once you open the page, first paste the text you created.

Choose your preferred voice.

In Ondoku Beta, you can also select a reading style.

For podcasts, "Narration," "Calm," and "Storytelling" are recommended.

You can also freely specify the reading style according to your preference.

Preparation is now complete.

Press "Generate Audio" to start generation.

Generation is completed quickly.

The screen will switch, and the audio file will play.

If the preview is OK, download it as an MP3.

By reading this text aloud, we were able to create audio like this.

Audio Sample

The workflow for creating podcast audio with Ondoku is now complete.

If you layer background music as you like, you can finish with a more professional podcast.

If you want to make it a dialogue format using two voices, you can also create it by switching speakers using Ondoku's conversation function.

As you can see, you can easily create podcast audio using Ondoku.

Why don't you also try creating your original podcast for free with Ondoku?

Tips for Creating Clear, High-Quality AI Podcast Audio

From here, we will explain some points for improving the quality of podcasts generated with AI.

Converting written language to spoken language is recommended

If you read blog article text as it is, it will inevitably result in audio with a stiff impression.

Therefore, we recommend using an AI service to convert written language into spoken language.

Unifying it with a polite "desu-masu" tone and keeping each sentence short will result in a script that can create easy-to-hear audio.

For conversion, it is recommended to ask a generative AI service like ChatGPT like this:

Prompt Example

"Please convert the following blog article text into spoken language for reading aloud in a podcast. Keep sentences short and unify with a polite desu-masu tone."

Target character count for one episode is 2,000 to 3,000 characters

A podcast script, depending on the reading speed of the AI voice, will result in an episode of about 10 minutes with 2,000 to 3,000 Japanese characters.

Since podcasts are often listened to "during commutes" or "while doing chores," about 10 to 15 minutes per episode is just the right length.

Recommended reading speed is 1.0 to 1.1x

The most easy-to-hear podcast reading speed is standard speed (1.0x) or a slightly faster 1.1x speed.

With "Ondoku", you can change the speed adjustment according to your preference.

In Ondoku Beta, it is also possible to change the speed by instructing the reading style.

Keep background music volume low

When layering background music, a volume balance of about 70 for narration and 30 for background music is best.

If the background music is too loud, it becomes difficult to hear the content, so the key is to adjust the balance so the voice can be heard clearly.

Free BGM materials can be downloaded for free from sites like "DOVA-SYNDROME" or "Amacha no Ongaku Koubou."

Recommended Distribution Destinations for Podcasts

Once your podcast audio file is ready, the next step is distribution.

If you are distributing a podcast for the first time, starting with Spotify for Podcasters is recommended.

You can create an account for free and start distributing immediately just by uploading your MP3 file.

Moreover, it automatically distributes not only to Spotify but also to other apps like Apple Podcasts and Amazon Music, so you can reach most listeners by registering once.

Distributing your podcast to YouTube is also recommended.

By posting as a video that combines audio with still images or slides, you can have users who searched for videos listen to it.

Summary of How to Create a Podcast Using AI Voice

In this article, we introduced how to create a podcast from text using AI services.

If you want to be particular about voice and reading style in a narration format, "Ondoku" is the best choice.

You can choose your favorite voice from over 650 voices, and speed and pitch can be freely adjusted.

Since commercial use is OK, you can use it with peace of mind for podcasts aimed at monetization.

If you want to create one easily in a dialogue format, NotebookLM or castmake are convenient, and if you are particular about audio quality, ElevenLabs is also useful.

Why not choose the tool that fits your purpose and start your own AI podcast?

■ 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.

Text-to-speech software "Ondoku" can read out 5000 characters every month with AI voice for free. You can easily download MP3s and commercial use is also possible. If you sign up for free, you can convert up to 5,000 characters per month for free from text to speech. Try Ondoku now.

HP: ondoku3.com
Email: ondoku3.com@gmail.com