How secure is Ondoku? Detailed answers about servers and more

Oct. 19, 2026

How secure is Ondoku? Detailed answers about servers and more


When creating audio with Ondoku, you need to enter the text you want read aloud.

You may be concerned that the text you enter could be misused or wonder whether it is safe.

Since audio may contain confidential company information, it is only natural to be cautious.

What kind of security does Ondoku have?

In this article, we’ll take a detailed look at Ondoku’s security.

Security concerns about Ondoku

Security is a concern when using a service. What kind of security does Ondoku have?

  • Are there any features to prevent unauthorized access when logging in to an account?
  • Is the text I enter stored on a server?
  • Which servers does Ondoku use?
  • Is my account accessible only to me?
  • Is there a risk that stored data could be viewed by a third party?
  • Has Ondoku received external security certifications?
  • Is communications encryption properly implemented?
  • Is Ondoku a SaaS service?
  • How is confidentiality handled?

We’ll answer each question carefully.

Are there any features to prevent unauthorized access when logging in to an account?

Yes. We have implemented a feature that locks an account and prevents login after authentication fails due to an incorrect password a certain number of times in a row.

To prevent unauthorized access through list attacks that attempt to log in, an account is locked and login is blocked if authentication fails due to an incorrect password a certain number of times in a row.

We cannot disclose the conditions for security reasons.

You can also enable two-factor authentication to prevent unauthorized access by third parties.

For more information about two-factor authentication, please see this article.

How to Set Up Two-Factor Authentication on Ondoku | A Guide to Enabling and Disabling It with Images

How to Set Up Two-Factor Authentication on Ondoku | A Guide to Enabling and Disabling It with Images

A detailed guide to setting up two-factor authentication on Ondoku. In addition to your password, a verification code helps prevent unauthorized access. We also explain the importance of backup codes and how to disable the feature.

Is the text I enter stored on a server?

The text you enter is stored on Ondoku’s servers.

The storage period varies depending on the member’s plan.

  • Non-members: 1 day
  • Free members: 30 days
  • Paid members: The period selected in settings (choose from 12, 24, or 36 months, or indefinitely. The default is 12 months.)
  • Business plan members: Until the member deletes their history

That is how long the data is stored.

Paid members can change the storage period in “History Retention Period” on the settings screen. For those who have been using the service for a while, a period based on their usage history has been set. Read-aloud history is automatically deleted after the selected period has elapsed (shared read-alouds are not deleted).

Ondoku uses Google Cloud for its servers.

Free and paid members can also delete data from Ondoku’s servers by deleting read-aloud history from their history using the deletion feature.
※ Deleting history does not increase the number of characters available for reading aloud.

Which servers does Ondoku use?

Ondoku uses Google Cloud Platform (Tokyo region).

Official site: Google Cloud

The servers are located in Tokyo.

Is my account accessible only to me?

Accounts are protected by

  • Email address
  • Password

Each is securely stored.

We recommend that you use a strong password, and avoid weak passwords, passwords used on other sites, and passwords that may have been exposed.

What makes a strong password?

  • To create a strong password, it is ideal to use at least 8 characters.
  • For even greater strength, using at least 14 characters is recommended.
  • A strong password should combine uppercase letters, lowercase letters, numbers, and symbols.

Source: https://www.benricho.org/password_meter/

Please keep your information secure.

Is there a risk that stored data could be viewed by a third party?

Read-aloud text and audio are stored on servers with robust security systems and can be viewed only by users who are logged in.

Has Ondoku received external security certifications?

We have not obtained certifications such as the PrivacyMark.

Do you conduct security assessments?

Yes, we do.

Ondoku conducts penetration tests at a scale 10 times greater than the standard set by IPA (Information-technology Promotion Agency, Japan), and has passed.

We thoroughly assess system vulnerabilities through rigorous penetration testing by external specialists to ensure security.

Is communications encryption properly implemented?

All pages of our service are encrypted with SSL/TLS, so third parties cannot view their contents.

Is Ondoku a SaaS service?

Yes, Ondoku is a SaaS service.

What is SaaS?

SaaS is an abbreviation for “Software as a Service,” pronounced “sass.”
It refers to a model in which software previously provided as packaged products is offered and used as a service over the internet.
SaaS may have the following characteristics:

Data can be stored on the internet.
Data can be accessed from PCs, smartphones, tablets, and other devices.
Multiple people can share and edit the same data.
Google Workspace (formerly G Suite) and Salesforce are examples of SaaS services.
Source: https://cloud-ace.jp

Ondoku can be used on devices such as

  • Computers
  • Smartphones
  • Tablets

from anywhere, as long as you have an internet connection.

How is confidentiality handled?

Confidentiality is described in detail in our Terms of Use.

Please see Article 22: Confidentiality.

Some of your data may be used by a limited number of our employees to check for errors or verify audio accuracy, or may be used as statistical data to improve audio technology and for research and development.

However, we do not publicly disclose the text you enter or the audio we create, nor do we provide your data to third parties.

We can also provide information for security-related forms

When using the service at a company, some companies may require you to fill out a security checklist or other form before you can use the service.

There are two ways to respond to security checklist questions:

  1. Please refer to the security checklist below and fill it out yourself.
  2. If you need us to review or fill out the form, we can do so for a fee.

For details about reviewing a completed form and fees for paid options, please see here.
Could you fill in the answers on security-related documents?

Could you fill in the answers on security-related documents? [Ondoku]

Could you fill in the answers on security-related documents? [Ondoku]

If you need a security checklist to use Ondoku, please see below.

Before contacting us, check the FAQ and the information required under the Act on Specified Commercial Transactions

Common questions from users are compiled in our FAQ.

The FAQ provides answers to questions about

  • How to use the service
  • Audio files and downloads
  • Payment methods
  • Business use

in a question-and-answer format. Most questions can be answered in the FAQ.

We also share detailed information about Ondoku on our blog, including regular updates and the latest developments for Ondoku.

Information about the operator is provided in the disclosure required under the Act on Specified Commercial Transactions.

Please make use of these resources.

■ AI voice synthesis software "Ondoku"

"Ondoku" is an online text-to-speech tool that can be used with no initial costs.

  • Supports 81 languages and regions, 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
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