// Privacy Policy
How Retro Web Tools handles your data
1. Introduction
This Privacy Policy ("this Policy") explains how Retro Web Tools ("this site") handles data. By using this site you are considered to have agreed to this Policy.
The site consists of a Japanese edition (under https://retro-web-tools.com/)
and an English edition (under /en/). This Policy applies to both, although as
described below the advertising shown differs between them.
This is an English translation of the original Japanese policy, provided for convenience. If the two versions differ, the Japanese version prevails.
2. What happens to the data you enter into a tool
Every tool on this site runs client-side, inside your own browser. The text, files, tokens and images you enter are processed on your device and are not transmitted to any server operated by this site.
This site does not receive, store or log the content of your input. You can verify this yourself by opening the network tab of your browser developer tools while you use a tool.
That said, as set out in section 3 (local storage) and sections 5 to 7 (analytics and advertising), data is saved inside your browser and third-party services do collect information. This is not a claim that no network traffic of any kind occurs.
3. What is saved inside your browser (local storage)
Some tools save a setting or your work in your browser local storage so that you can pick up where you left off. The data is held on your own device only; neither this site nor any third party can read it.
| Storage key | Tool | What is stored |
|---|---|---|
rwt:emoji-recent | Emoji Search | The emoji you recently copied |
rwt:mermaid-code | Mermaid Preview | The diagram source you typed into the editor |
rwt:tz-cities | Time Zone Converter | The list of cities you selected |
rwt:tz-mode | Time Zone Converter | The display mode (world clock or time conversion) |
rwt:unit-category | Unit Converter | The unit category you last opened |
You can delete this at any time through your browser settings, under an option such as "clear browsing data" or "clear site data". In a private browsing window it is discarded when you close the window.
Tools not listed above keep nothing: closing the tab discards what you entered.
4. Collection of personal information
This site does not collect personal information directly. There is no account registration and no sign-in, and you are never asked for a name, email address, postal address or telephone number.
The third-party services described below do, however, automatically collect IP addresses, device and browser information, and identifiers such as cookies. In some jurisdictions that counts as personal data, which is why it is disclosed here.
5. Analytics (Google Analytics)
This site uses Google Analytics 4, provided by Google LLC, to understand how the site is used and to improve it. Google Analytics uses cookies and similar technologies to collect usage information.
The information collected includes which pages are viewed, how long visitors stay, the referring source, the browser, operating system and device type, and an approximate location inferred from the IP address. It does not include information that directly identifies you, such as a name or an email address.
For details of how this data is collected and processed, see How Google uses information from sites or apps that use our services . You can refuse collection by installing the Google Analytics Opt-out Browser Add-on or by disabling cookies in your browser settings.
6. Advertising (Google AdSense)
This site uses Google AdSense, a third-party advertising service. Third-party vendors, including Google, may use cookies to serve advertising based on your prior visits to this site or to other websites.
You can turn off personalised advertising in Google Ad Settings. For ways to opt out of cookie use by other third-party vendors, see aboutads.info or, in Europe, youronlinechoices.eu.
Serving advertising causes your browser to send requests to Google servers, and Google therefore receives your IP address and user agent. Data you enter into a tool is not sent to any advertising provider.
7. Affiliate programme (Amazon Associates)
Retro Web Tools is a participant in the Amazon Associates Programme, an affiliate advertising programme designed to provide a means for sites to earn referral fees by advertising and linking to Amazon.co.jp.
Japanese tool pages may show a panel of products related to the tool, labelled "PR". This panel is not shown on English pages.
When the panel loads, a request is sent to an advertising API operated by this site, carrying an identifier for the tool page being viewed. That request does not include anything you have entered into the tool. Product images are loaded from Amazon servers, so Amazon receives your IP address and user agent.
If you click through to Amazon, your activity there is governed by Amazon's own privacy notice. See the Amazon.co.jp Privacy Notice for details.
8. Third-party services used
| Service | Provider | Purpose | Applies to |
|---|---|---|---|
| Google Analytics 4 | Google LLC | Measuring site usage and improving the site | All pages |
| Google AdSense | Google LLC | Serving advertising and measuring its performance | All pages |
| Amazon Associates Programme | Amazon.com, Inc. and its affiliates | Showing product links and tracking referrals (Japanese tool pages only) | Japanese pages only |
All other resources, including the web fonts (Press Start 2P and VT323), are served from this site rather than from a third-party CDN.
9. Managing cookies
This site does not set cookies of its own. The cookies described above are set by Google Analytics and Google AdSense.
You can refuse or delete cookies at any time in your browser settings. The tools on this site continue to work with cookies disabled.
10. If you are in the EEA, the UK or Switzerland
When you visit from one of these regions, a consent message served through a Google-certified consent management platform asks for your consent to the use of advertising and analytics cookies. If you do not consent, personalised advertising is not served.
You can change your choice at any time through that same message. Under the GDPR you have the right to access, rectify and erase data relating to you, to restrict processing, to data portability, and to object to processing.
Where those rights concern data held by Google, they are handled through the contact points named in Google's Privacy Policy. Because this site does not retain anything you enter into a tool, there is generally no data held by this site for it to erase or correct.
11. If you are a California resident
This site does not "sell" personal information within the meaning of the California Consumer Privacy Act (CCPA/CPRA). Where information is "shared" with third parties for advertising, the opt-out routes described in section 6 are available to you.
12. Disclosure to third parties
Apart from the automatic collection carried out by the third-party services listed in this Policy, this site does not disclose information about visitors to third parties, except where disclosure is required by law.
13. Children
This site is not directed at children under 13 and does not knowingly collect personal information from them. If it emerges that such information has been collected, it will be deleted promptly.
14. Disclaimer
The tools on this site are provided "as is", without warranty of any kind, express or implied, as to their accuracy, completeness, reliability or fitness for a particular purpose.
The operator of this site is not liable for damage arising from use of the site, except where that damage results from the operator's wilful misconduct or gross negligence. When the output of a tool informs a professional judgement or the handling of important data, verify the result by other means.
The operator is not responsible for the content of third-party advertising, or for the products and services linked from it.
15. External links
This site contains links to external websites. The operator of this site is not responsible for the privacy practices or the handling of information on those sites. Please review the policy of each site you visit.
16. Changes to this Policy
This Policy may be changed without prior notice. A revised version takes effect from the moment it is published on this page. Where a significant change is made, the last-updated date below is revised.
17. Contact
Questions about this Policy, or requests concerning the handling of data, can be sent to crasanstudy@gmail.com.
Last updated: September 2026