21K Tools

Quick summary — what you actually need to know

The key points

  • The vast majority of tools run 100% in your browser — nothing is sent to any server
  • No account, no email, no sign-up is required to use anything on the site
  • URL Shortener: the link you shorten is stored so redirects can work — explained below
  • QR Code Generator (file upload only): uploaded files go to Cloudinary to generate a public URL — explained below
  • Google Analytics is used for anonymised traffic data — your identity is never tracked
  • This site uses Google AdSense to display ads, which uses cookies to personalise ads — explained below
  • No data is sold to third parties, and ad personalisation can be turned off in your Google Ad Settings

If you only use the calculators, PDF tools, image tools, QR generator (text/URL input), or any browser-based tool — nothing leaves your device. Full stop.

How the tools actually handle your data

Understanding this section helps you decide what's safe to run through which tool. The distinction between browser-based tools and server-side tools is real and meaningful — especially if you're processing sensitive documents.

Browser-based tools — your data stays on your device

The following tools do all their processing using JavaScript and WebAssembly running directly in your browser tab. When you upload a file, it's read into your browser's memory. The processing happens on your own device. The result is generated locally and offered to you as a download. At no point is your file sent over the internet to any server.

  • All PDF tools — merge, split, compress, convert, OCR, rotate, add watermark
  • All image tools — resize, compress, convert, crop
  • QR Code Generator (text and URL input modes) and QR Scanner
  • File Converter
  • Age Calculator, Interest Calculator, Time Calculator, Unit Converter and all other calculators

Closing or refreshing the tab clears everything. There's nothing stored anywhere because nothing was ever sent anywhere.

For sensitive documents — contracts, medical records, financial statements — the browser-based tools are the appropriate choice. Your file genuinely does not leave your device.

URL Shortener — server storage is how it works

When you create a short link, the original URL and its generated short code are stored in our database. This isn't optional — it's how redirects work. When someone clicks the short link, their browser asks our server where to redirect them, and the server looks up the answer. Without storing that mapping, the redirect can't happen.

  • The URL you submit is stored on our servers alongside its short code
  • We don't associate your URL with any account, email address, or IP address
  • Short links may be retained indefinitely to keep them functional
  • If you want a link removed, email us at contact@21k.tools
  • Don't shorten URLs that contain private or sensitive information in the URL string itself

QR Code Generator — file upload mode

The QR code generator has a mode that lets you generate a QR code linking directly to a file (a PDF, image, etc.). For that to work, the file needs to be publicly accessible via a URL — which means it needs to be hosted somewhere. We use Cloudinary, a third-party cloud media platform, for this.

  • Uploaded files are stored on Cloudinary's servers and become publicly accessible via the generated URL
  • Anyone with the QR code or its URL can access the file — that's the point of this feature
  • We don't link the upload to any personal identity
  • Don't upload files containing sensitive, private, or confidential information through this feature
  • Cloudinary's own privacy practices apply to stored files: cloudinary.com/privacy
QR codes for text, URLs, WiFi credentials, contact cards, etc. — those all work in-browser with no upload. Only the "link to a file" mode uses Cloudinary storage.

Analytics — how we understand site usage without tracking individuals

We use Google Analytics to understand which tools are being used, how people navigate the site, and where things might be confusing. This helps prioritise what to improve and what to build next.

Google Analytics collects anonymised and aggregated data: which pages were visited, roughly where in the world visitors are (country/city level, not precise location), what type of browser and device was used, and how long was spent on each page. IP anonymisation is enabled, so full IP addresses are not stored by Google Analytics. This data is never tied to a personal identity.

If you want to opt out of Google Analytics tracking entirely, the Google Analytics Opt-out Browser Add-on works across all sites. Google processes analytics data under its own Privacy Policy.

Cookies

We use three types of cookies. Essential cookies handle basic session functionality — they're deleted when you close your browser and are not used for tracking. Google Analytics sets cookies (_ga, _gid) for the anonymised tracking described above. Google AdSense and its advertising partners also set cookies (including the DART cookie) to serve ads based on your visits to this and other websites — see the Advertising section below for details and how to opt out.

What we don't do — being explicit about it

These aren't just legal disclaimers. They describe actual choices made in how this site is built.

  • We don't collect your name, email address, or any personal identifier for tool usage
  • We don't track or log IP addresses for user profiling
  • We don't use tracking pixels, fingerprinting, or behavioural profiling
  • We don't sell data to anyone
  • We don't share data with third parties for advertising purposes
  • We don't require account creation or login for any tool
  • We don't store the files you process through browser-based tools — they never reach our servers

Your rights and how to exercise them

For the browser-based tools — the majority of the site — we hold no data linked to you, so there's nothing to access, correct, or delete. For the two server-side features:

  • URL Shortener: If you know your short link and want it removed, email us and we'll delete it
  • QR Code file upload: Files are on Cloudinary — contact us and we'll request deletion
  • Contact queries: Email correspondence can be deleted on request at any time

For any privacy-related request, contact us at contact@21k.tools or through the Help Center. We take these seriously and respond promptly.

If you contact us

If you email us at contact@21k.tools or use the Help Center form, we'll receive and store your message to respond to you. That's the only purpose it's used for — it's not shared with anyone else.

Advertising — Google AdSense

This site uses Google AdSense to display advertising. Google, as a third-party vendor, and other advertising partners use cookies (including the DART cookie) to serve ads based on a user's prior visits to this site and other sites on the internet. This allows Google and its partners to serve ads that may be more relevant to you.

You can opt out of personalised advertising by visiting Google's Ads Settings. Alternatively, you can opt out of a third-party vendor's use of cookies for personalised advertising by visiting aboutads.info/choices or the Network Advertising Initiative opt-out page. Full detail on how Google uses data for advertising is available at policies.google.com/technologies/ads.

If you are located in the European Economic Area or the UK, ads served to you may be subject to consent requirements under Google's EU User Consent Policy; where applicable, we obtain or display the necessary consent before personalised ads are shown.

We don't control the content of individual ads — that's determined by Google's ad network — but we don't permit ad placements that are deceptive, malicious, or unrelated to the site's tools and content.

Children's privacy

21K Tools is not directed at children under 13. We don't knowingly collect information from children. If you believe a child has submitted personal information to us, contact us at contact@21k.tools and we'll address it promptly.

Changes to this policy

If something material changes about how data is handled — like if we add advertising, or introduce a new feature that involves server-side processing — we'll update this page and change the "Last Updated" date at the top. For significant changes, we'll also post a notice on the site.

Questions

If something in this policy is unclear, or if you have a question that isn't answered here, email us at contact@21k.tools. We respond to everything.

We built 21K Tools because we were frustrated by tracking-heavy, ad-stuffed online tools. This policy reflects how the site actually works — not how we wish it worked.

Last Updated: June 29, 2026

Explore Our Tools

Discover our collection of powerful tools to make your work easier. Visit 21k.tools for all available tools and resources.

URL Shortener

Create short, shareable links instantly.

QR Tools

Generate and Scan QR codes smartly.

PDF Tools

Merge, split, and edit PDF files easily.

Unit Converter

convert units from one to another easily .

File Converter

Convert between multiple file formats.

Image Resizer

Resize and optimize images for any use.

Time Calculator

Calculate time in hours, minutes, and seconds

Age Calculator

Calculate age in years, months, and days.

Interest Calculator

Calculate simple and compound interest.

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