Privacy policy
What happens to what you type into the tools, what your browser stores, and what our host handles.
Last updated 6 October 2026
In short
- 22 of the 25 tools keep what you type in your browser. What you type or open in those isn't sent to our servers; the table below lists each tool. The DNS lookup also runs in your browser, but sends the domain name to the public DNS resolver you choose (Cloudflare or Quad9), not to us (see below). What's my IP uses our server: it receives your IP address, which every request carries (see below). MAC address lookup uses our server: it receives the vendor prefix only: the first 6 hex digits of the MAC address (see below).
- The site sets no cookies of its own and runs no ads. It counts visits with Cloudflare Web Analytics, which uses no cookies or browser storage (see below).
- Our host, Cloudflare, handles the technical data needed to deliver the pages, such as your IP address.
What you type or open in the tools
Each tool marked "your browser" below processes your input in your browser. It isn't sent to our servers, and it isn't put into the page address. Each tool page also shows how that tool handles your input, just before its questions.
| Tool | Runs in | Input sent to us | Sent elsewhere |
|---|---|---|---|
| JSON formatter | your browser | Nothing | Nothing |
| Regex tester | your browser | Nothing | Nothing |
| Text diff | your browser | Nothing | Nothing |
| Case converter | your browser | Nothing | Nothing |
| YAML to JSON | your browser | Nothing | Nothing |
| CSV to JSON | your browser | Nothing | Nothing |
| SQL formatter | your browser | Nothing | Nothing |
| Subnet calculator | your browser | Nothing | Nothing |
| VLSM calculator | your browser | Nothing | Nothing |
| What's my IP | our server | Your IP address, which every request carries | Nothing |
| DNS lookup | your browser | Nothing | The domain name, to the public DNS resolver you choose (Cloudflare or Quad9) |
| IP range to CIDR | your browser | Nothing | Nothing |
| MAC address lookup | our server | The vendor prefix only: the first 6 hex digits of the MAC address | Nothing |
| Base64 encoder | your browser | Nothing | Nothing |
| URL encoder | your browser | Nothing | Nothing |
| HTML entity encoder | your browser | Nothing | Nothing |
| QR code generator | your browser | Nothing | Nothing |
| JWT decoder | your browser | Nothing | Nothing |
| Hash generator | your browser | Nothing | Nothing |
| UUID generator | your browser | Nothing | Nothing |
| Password generator | your browser | Nothing | Nothing |
| Timestamp converter | your browser | Nothing | Nothing |
| Time zone converter | your browser | Nothing | Nothing |
| Cron parser | your browser | Nothing | Nothing |
| chmod calculator | your browser | Nothing | Nothing |
The DNS lookup
When you press Look up, your browser asks the public DNS resolver you choose, Cloudflare (1.1.1.1) or Quad9 (9.9.9.9), or both when you compare them, for the domain's records, over an encrypted connection (DNS over HTTPS). The request goes straight from your browser to that resolver, so the domain isn't sent to our servers, and it isn't put into the page address. Nothing is sent while you type, only when you press Look up.
The resolver receives the domain name, your IP address and the usual browser request data, such as your browser's name and that the request came from this site (the page sends no referrer beyond that, and the answer isn't kept in your browser's cache). It handles them under its own privacy policy (linked above); we don't choose what it logs.
What's my IP
When you open that page, or press Check again, your browser sends one request to our server, a Cloudflare Worker. Every request carries your IP address. Our server reads it, together with what Cloudflare attaches to each request: the approximate location of the address from IP geolocation (country, region, city, postal code, continent and time zone; not coordinates), its network, and how you connected (the Cloudflare data center, HTTP and TLS versions, the cipher and the round-trip time). It sends them back to show on the page, only to you. It doesn't look them up anywhere else, and it doesn't keep a log of these requests. The browser name, languages and user agent shown there are read by the page itself, which doesn’t send them on; your browser sends its user agent and languages with every request anyway, as described under “Our host, Cloudflare”.
To stop automated misuse, Cloudflare limits how many of these requests one address can make in a few seconds, which means it counts them by address for a short time. When a request is blocked for going over that limit, Cloudflare records the block, including the address, in the security log of our Cloudflare account. Cloudflare otherwise handles the request like any other, as described under "Our host, Cloudflare" below.
The MAC address lookup
When you press Look up, or pick an example, your browser sends our server, a Cloudflare Worker, the first 6 hex digits of each address you typed (the vendor prefix, which names a manufacturer, not a device), in the body of the request, not in the page address. With several addresses, it asks once per distinct prefix, one request at a time. It sends nothing for addresses that have no vendor (locally administered or broadcast), and asks once per prefix while the page is open. Our server answers with the registry entries under that prefix, and your browser picks the match; the rest of the address isn't sent. Our server doesn't keep a log of these requests. Like every request, this one carries your IP address, and the rate limit described above applies to it too.
What your browser stores
The site keeps two things in your browser's local storage, and only when you ask for them. Neither is sent anywhere.
| Entry | What it holds | When it's saved | How to remove it |
|---|---|---|---|
theme | Your choice of light or dark theme | When you use the theme button | Clear this site's data in your browser |
tu:json:recent, tu:json:recent:on | Up to 5 recent documents from the JSON formatter, and whether the option is on | Only after you turn on "Remember recent files on this device" | Turn the option off: that deletes the saved documents |
If you haven't chosen a theme, the site follows your device's light or dark setting and stores nothing.
Our host, Cloudflare
Cloudflare, Inc. delivers this site from its global network. To do that, and to protect the site from abuse, it processes your IP address, the page you ask for, your browser's user agent and similar request data, which may happen outside your country. Cloudflare does this for us under its customer data processing addendum, and also uses some of this data for its own security purposes, as its privacy policy describes. We don't receive a log of individual visits.
If Cloudflare shows you a security check, it may set a cf_clearance cookie to remember that you passed it. Cloudflare explains its cookies here.
Visit counts
To count visits and see how fast pages load, each page loads a small script from Cloudflare (Cloudflare Web Analytics, from static.cloudflareinsights.com). It sends Cloudflare the page address, the page you came from, your browser and device type, your country and the page's load timings, through this site's own address (/cdn-cgi/rum). It uses no cookies or browser storage, and Cloudflare says it doesn't fingerprint visitors or track them across sites. What you type or open in the tools isn't part of it: the tools don't put your input into the page address. We see only totals, such as visits per page and per country.
If you email us
If you write to hello@techutils.net, we use your address and message only to reply to you, and delete them when they're no longer needed for that. We don't share them. Our email provider handles messages to deliver them.
Children
The tools are for a general audience and don't ask anyone for personal information. The only personal information we hold is email that someone chooses to send us.
Your rights
You can ask us what personal information we hold about you, and ask us to correct or delete it. Under India's Digital Personal Data Protection Act you can also nominate someone to exercise these rights for you. Email hello@techutils.net; you don't need any account or ID. We reply within 30 days.
If you have a complaint, email us first and we'll respond within 30 days. You can also complain to the Data Protection Board of India.
Changes to this policy
If we change how the site handles data, for example by adding ads, we'll update this page before the change goes live and change the date at the top.