Free online tools that don't keep your data
QR codes, passwords, formatters, encoders and converters that work instantly and keep nothing you enter.
- 31 tools
- 8 categories
- 7 languages
Code Formatters & Validators
5- XML FormatterPaste XML to indent it readably or collapse it to one line, and to check that it is well formed. Errors point at the exact line and column. Everything runs in your browser, so nothing is uploaded.
- YAML ValidatorPaste YAML to check it and convert it to JSON, or switch direction to turn JSON back into YAML. Errors report the exact line and column. Everything is parsed in your browser, so manifests carrying secrets are never uploaded.
- JSON FormatterPaste JSON to indent it readably and check that it parses, with the line and column of any error and a collapsible tree for finding your way around an unfamiliar response.
- JSON ComparePaste two JSON documents to see every added, removed and changed value listed by path. Key order is ignored, so only real differences are reported.
- JSON StringifyTurn a JSON document into an escaped string you can paste into code, or reverse an escaped string back into readable JSON.
Network Tools
1Encoders & Decoders
6- CSR DecoderPaste a certificate signing request or an X.509 certificate to read what is inside it: subject, alternative names, key algorithm and size, validity dates, extensions and fingerprints. Everything is decoded in your browser and nothing is ever uploaded.
- Base64 Encoder & DecoderEncode text to Base64 or decode it back. Unicode is handled correctly, so Japanese, Chinese, Korean and emoji all round-trip without corruption.
- URL Encoder & DecoderPercent-encode text for use in a URL, or decode it back. Choose whether you are encoding one query value or an entire URL, because the two need different escaping.
- Hash & HMAC GeneratorType or paste text to see its MD5, SHA-1, SHA-256 and SHA-512 hashes at once, or switch to HMAC to sign it with a secret key. Everything runs in your browser, so neither your text nor your key leaves your device.
- JWT DecoderPaste a JWT to read its header and payload and see when it expires. Decoding happens entirely in your browser, so the token never leaves your device.
- JWT GeneratorBuild a JWT payload, pick an algorithm and sign it with your secret. Signing happens entirely in your browser, so the secret never leaves your device.
Generators
7- Mock Data GeneratorDefine the fields you need and generate up to 1,000 rows of realistic fake data as JSON, CSV or SQL insert statements. Everything is generated in your browser, so nothing is uploaded and no real personal data is involved.
- UUID GeneratorGenerate UUIDs in your browser, either random v4 or time-sortable v7. Choose how many you need and copy them individually or all at once.
- Password GeneratorGenerate strong random passwords in your browser, with the actual entropy in bits shown rather than a vague strength meter. Nothing is transmitted or stored.
- Random Number GeneratorGenerate random numbers in any range, as integers or decimals, with an option for no repeats. Draws come from the browser cryptographic random source rather than Math.random.
- QR Code GeneratorGenerate a QR code for a URL, text or Wi-Fi network and download it as PNG or SVG. Everything happens in your browser, so nothing is uploaded and the code never expires.
- Cron Expression Generator and ParserWrite a cron expression and see the next times it will actually run. Every field is validated, and schedules that can never fire are flagged.
- Wheel SpinnerPaste a list of names or numbers and spin the wheel to pick one at random. The winner is drawn before the wheel moves, so the animation cannot influence the result.
Converters
6- Unix Timestamp ConverterConvert a Unix timestamp to a readable date or the other way round. The unit is detected automatically and every result shows its time zone.
- Case ConverterPaste text to see it in every case at once, from camelCase and snake_case to Title Case and sentence case. Everything runs in your browser.
- Binary ConverterConvert a number between binary, octal, decimal and hexadecimal, or convert text to binary and back. Values stay exact at any size, including well beyond 64 bits.
- Unit ConverterConvert between metric and imperial units for length, weight, temperature, area, volume, speed, data and time. Every conversion uses the exact defined factor, so results are not thrown off by floating-point error.
- Image ConverterConvert an image between PNG, JPG and WebP. The file is decoded and re-encoded inside this page, so it never leaves your device and keeps working with no connection.
- Image ResizerResize an image to exact pixels, a percentage, or a maximum longest edge. The resizing happens in this page, so the file never leaves your device.
Testers
2- Regex TesterWrite a pattern and see every match highlighted as you type, with capture groups and positions. Matching runs in a background thread, so even a catastrophically backtracking pattern will not freeze the page.
- Text DiffPaste two texts to see exactly what changed, line by line and word by word. Everything runs in your browser, so neither version is uploaded.
Color Tools
1Text Tools
3- Word CounterCount words, characters, sentences and paragraphs as you type, with reading time and the most used words. Everything runs in your browser, so your text is never uploaded.
- Emoji Copy and PasteClick any emoji to copy it, then paste it anywhere. Browse by category or search in your own language - every emoji here is a standard Unicode character, so it will look right wherever you paste it.
- Data SanitizerPaste a log, a support ticket or a prompt and every email address, phone number, card number, IP address and API key in it is replaced before you share it. Optional on-device AI also catches names and street addresses.
We don't keep your data
Whatever you paste into a tool is not stored, logged or shared. Most tools do the work entirely in your browser, so there is nothing to keep in the first place; where a tool needs a server it will say so on its own page, and the request still is not retained.
No signup, no limits
No account, no daily quota, no file-size ceiling beyond what your own browser can hold. Open a tool, use it, close the tab.
Built to be fast
Static pages with no heavy framework on the tool itself, so they load instantly and work the same on a phone as on a desktop.
Why another set of tools?
Most online tools upload whatever you give them and load slowly enough that doing the job by hand would have been quicker. These do the opposite: the processing happens on your own machine, the pages are small, and the tool itself is the first thing you see rather than something you have to scroll to find. Some are aimed at people who write code and some at anyone with a link to turn into a QR code, but they all work the same way. Every one is available in English, Japanese, Traditional Chinese, Korean, Portuguese, Spanish and Indonesian.
Common questions
- Are these tools really free?
- Yes. There is no account, no trial and no paid tier gating features. Nothing is held back behind a signup.
- Is anything I paste sent to a server?
- No. What you enter is not stored, logged or shared. Today every tool listed here processes your input inside your browser, so the data never leaves your device in the first place.
- Can I use these at work or for commercial projects?
- Yes. There are no usage restrictions. Because nothing is transmitted, they are also usable inside environments where pasting data into a website would normally be against policy.
- Do I need to install anything?
- No. Everything runs in a normal browser tab with no extension, download or configuration.
- Which languages are supported?
- English, Japanese, Traditional Chinese, Korean, Portuguese, Spanish and Indonesian. Every tool, description and help text is translated rather than machine-generated, and the language switcher keeps you on the same page.