Free Data Tools — Generate, Compare, Format Text

Developers and testers constantly need data that is not real: unique identifiers for a database row, a block of placeholder text for a layout, a set of fake users for a demo, a QR code for a link. This page gathers the DevStackKit tools that generate, compare and tidy data so you can get on with the actual task.

Generators create the values on your device using the browser's own random number source, so they are suitable for test data and examples. Comparison and replacement tools help you find what changed between two lists or documents and fix it in bulk. Nothing you paste is uploaded.

Pick the GUID generator for unique ids in several formats, the dummy data generator for realistic sample records, lorem ipsum for placeholder copy, the string replacer and list compare for bulk edits, and the QR code generator for links and text. All of them offer a sample so you can see what to expect before you use your own input.

All Data tools

26 tools

Text CompareSpot the differences between two texts

Code Diff CheckerCompare two pieces of code side by side

Case ConverterChange text to UPPER, lower, Title case

Slug GeneratorMake clean web addresses from titles

GUID GeneratorCreate unique IDs

Dummy Data GeneratorCreate realistic sample data for tests

String Replacer / List CompareFind and replace text, or compare lists

Lorem Ipsum GeneratorPlaceholder text for designs

Robots.txt GeneratorControl which pages search engines read

QR Code GeneratorMake a QR code for links, Wi-Fi or UPI

Word & Character CounterCount words, characters and reading time

Random String GeneratorCreate random codes and tokens

Barcode GeneratorMake product barcodes

QR Code ScannerRead a QR code from a picture

ASCII Art Text GeneratorTurn text into big ASCII letters

Text ExtractorPull emails or links out of any text

Date Difference CalculatorCount days between two dates

Date Add / SubtractAdd or subtract days from a date

Date Format ConverterChange how a date is written

Week Number CalculatorFind the week number of any date

JSON Key SorterSort JSON keys A to Z

JSON Flatten / UnflattenTurn nested JSON into flat keys and back

Fake CSV GeneratorCreate sample spreadsheets for testing

Number to WordsWrite numbers in words (₹ lakh, crore)

Line ToolsRemove duplicates, sort and clean lists

WhatsApp Link GeneratorCreate a WhatsApp chat link and QR

Frequently asked questions

Is the generated data random enough for tests?

Yes for test data and examples. Values come from your browser's random number source. For secrets such as passwords and keys, use the security tools, which are built for that.

Is any generated or pasted data stored?

No. Generators and comparison tools work in your browser and nothing is uploaded. Only the things you choose to save, such as favorites, are kept in this browser.

How many items can I generate at once?

Each generator shows its own limit on the page, chosen so the page stays fast. If you need more, generate again or download the result in batches.

Can I compare two long documents?

Yes. Text Compare and the Diff Checker show added, removed and unchanged lines side by side, up to a few thousand lines per side so the browser stays responsive.

More tool groups

JSON tools · Converters · All tools