What developer tools does Texterfly offer?

Texterfly offers 10 free developer tools: a JSON Formatter & Validator, an All-in-One Data Converter (JSON/CSV/XML/YAML), a JWT Decoder & Analyzer, a Cron Job Generator & Explainer, a QR Code Generator, a Password Generator, a Unix Timestamp Converter, a Lorem Ipsum Generator, an Interactive Data Visualization Builder, and a CSS Neumorphism Generator. All are free, browser-based, and require no signup.

How do I format and validate JSON online?

Paste your JSON into the JSON Formatter & Validator tool. It automatically detects syntax errors with precise line and column numbers, beautifies the output with proper indentation, and offers a minify option to compress the JSON for production use. You can also upload a .json file or fetch JSON from a URL.

How do I convert JSON to CSV (or CSV to JSON)?

Use the All-in-One Data Converter & Formatter. Paste your JSON or CSV, select the output format, and the conversion happens instantly. The tool also supports XML and YAML conversion, file upload, URL fetching, and JSONPath queries for extracting specific fields before converting.

How do I decode a JWT token?

Paste your JWT into the JWT Decoder & Analyzer. The tool instantly splits it into the header, payload, and signature sections, decodes the base64url encoding, checks expiration (exp claim), and detects common security issues like the "none" algorithm attack. For HS256 tokens, you can enter a secret key to verify the signature.

How do I write a cron job expression?

A cron expression has five fields: minute (0-59), hour (0-23), day of month (1-31), month (1-12), and day of week (0-7). Examples: "0 9 * * 1" runs every Monday at 9 AM; "0 0 * * *" runs daily at midnight; "*/15 * * * *" runs every 15 minutes. Use the Cron Job Generator to build and validate expressions visually with a real-time English translation.

What makes a password strong?

A strong password has: at least 16 characters (longer is better), a mix of uppercase and lowercase letters, numbers, and symbols, no dictionary words or predictable patterns, and is unique (never reused across accounts). The Password Generator creates cryptographically random passwords meeting all these criteria and shows an entropy-based strength score.

What is a Unix timestamp?

A Unix timestamp is the number of seconds elapsed since January 1, 1970, 00:00:00 UTC (the Unix Epoch). It is the universal standard for representing time in computing. A 10-digit number is seconds; 13 digits is milliseconds; 16 digits is microseconds; 19 digits is nanoseconds. Use the Timestamp Converter to convert between Unix time and human-readable dates.

What is neumorphism in CSS?

Neumorphism (also called Soft UI) is a design style that uses a combination of two box shadows — one light and one dark — on a background that matches the element's color to create a soft, extruded or pressed appearance. The CSS Neumorphism Generator creates the exact box-shadow CSS code for any color, size, and depth with a live preview.

What is the structure of a JWT?

A JWT (JSON Web Token) consists of three base64url-encoded parts separated by dots: Header.Payload.Signature. The Header specifies the token type (JWT) and signing algorithm (e.g. HS256). The Payload contains claims — statements about the user or session like "sub" (subject), "exp" (expiration), "iat" (issued at), and "iss" (issuer). The Signature verifies that the token was not tampered with.

Are these developer tools free?

Yes. All 10 developer tools on Texterfly are 100% free with no registration, subscription, or payment required.

Is my code or data private?

Yes. All processing runs entirely in your browser using JavaScript. Your JSON, JWT tokens, passwords, and data are never sent to any server or stored anywhere. This makes the tools safe for sensitive tokens, credentials, and confidential data.

Can I use these tools for commercial projects?

Yes. All Texterfly developer tools are free for both personal and commercial use. There are no licensing restrictions on how you use the output.

Back to Developer Tools

Mock JSON Data Generator

Generate realistic fake JSON test data — names, emails, addresses, IDs — for API testing and prototyping. Custom schema, reproducible seeds, JSON/NDJSON export. Free, no sign-up.

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Developer Tools

Quick Presets

Schema

Options

Records 10

Seed

Same seed + schema always produces the same data — useful for repeatable tests.

Pretty-print

Output as NDJSON

[
  {
    "id": 1,
    "firstName": "Anthony",
    "lastName": "Moore",
    "email": "anthony.moore18@hotmail.com",
    "phone": "(418) 699-8789",
    "createdAt": "2024-01-22"
  },
  {
    "id": 2,
    "firstName": "Elizabeth",
    "lastName": "Scott",
    "email": "elizabeth.scott20@hotmail.com",
    "phone": "(749) 688-1034",
    "createdAt": "2024-01-23"
  },
  {
    "id": 3,
    "firstName": "Liam",
    "lastName": "Williams",
    "email": "liam.williams27@gmail.com",
    "phone": "(348) 826-5773",
    "createdAt": "2024-12-13"
  },
  {
    "id": 4,
    "firstName": "Michael",
    "lastName": "King",
    "email": "michael.king32@hotmail.com",
    "phone": "(229) 241-6009",
    "createdAt": "2023-10-23"
  },
  {
    "id": 5,
    "firstName": "Elizabeth",
    "lastName": "Sanchez",
    "email": "elizabeth.sanchez74@protonmail.com",
    "phone": "(606) 363-3557",
    "createdAt": "2024-06-01"
  },
  {
    "id": 6,
    "firstName": "John",
    "lastName": "Clark",
    "email": "john.clark92@gmail.com",
    "phone": "(954) 544-9480",
    "createdAt": "2024-09-23"
  },
  {
    "id": 7,
    "firstName": "Robert",
    "lastName": "Smith",
    "email": "robert.smith61@protonmail.com",
    "phone": "(262) 775-9413",
    "createdAt": "2024-06-12"
  },
  {
    "id": 8,
    "firstName": "Fatima",
    "lastName": "Davis",
    "email": "fatima.davis12@protonmail.com",
    "phone": "(650) 932-4905",
    "createdAt": "2023-11-06"
  },
  {
    "id": 9,
    "firstName": "Susan",
    "lastName": "White",
    "email": "susan.white30@hotmail.com",
    "phone": "(874) 756-9946",
    "createdAt": "2023-03-23"
  },
  {
    "id": 10,
    "firstName": "Sarah",
    "lastName": "Perez",
    "email": "sarah.perez69@outlook.com",
    "phone": "(828) 923-1842",
    "createdAt": "2024-01-20"
  }
]

All data is generated entirely in your browser from static name/word banks — nothing is sent to a server, and no data is fetched from a real API. Every value is fictional and does not correspond to a real person, address, or company.

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Free Mock JSON Data Generator — Realistic Test Data, No Sign-Up

Building a schema field by field, or starting from a preset like User, Product, or Address, generates realistic-looking fake names, emails, addresses, and IDs instantly — no external API, no account, and no real personal data involved. Every value comes from static name and word banks running entirely in your browser. Use the seed field to get the exact same dataset again later, which is handy for repeatable tests and fixtures.

Need something else for your workflow? Browse the rest of the developer tools for more free utilities.

Why Use a Seed?

Unlike a purely random generator, this tool uses a seeded pseudorandom number generator — the same seed and schema will always produce the exact same dataset. That means you can share a seed with a teammate to reproduce the same fixtures, write a test that expects specific-looking data, or regenerate a dataset you liked without saving the raw JSON. Change the seed (or hit "New") whenever you want a fresh dataset from the same schema.

🔁 Reproducible by default

The same seed + schema combination always generates identical data — useful for consistent test fixtures.

📄 JSON array or NDJSON

Export as a standard JSON array for most APIs, or newline-delimited JSON (NDJSON) for streaming and log-style pipelines.

Common Uses for Mock JSON Data

🔌

Prototype an API before the backend exists

Stub out endpoint responses with realistic-shaped data so frontend work can start before real data is available.

🧪

Write repeatable tests

Use a fixed seed to generate the same fixture data every test run, without hardcoding dozens of fake records by hand.

🎨

Populate a UI for design review

Fill tables, cards, and lists with realistic names and values instead of "Lorem Ipsum" or "Test User 1" placeholders.

📊

Load-test with larger datasets

Generate hundreds of records at once to see how a table, chart, or component performs with more realistic data volume.

🔒

Avoid using real personal data in dev/staging

Keep real user data out of lower environments entirely by seeding them with generated fake records instead.

Frequently Asked Questions

Is any of this real personal data?

No. Every name, email, address, and company is assembled from static word banks and random combinations — none of it corresponds to a real person, place, or business.

Does this call an external API to generate the data?

No. Everything is generated client-side in your browser from built-in data banks. No network request is made to produce the output.

What does the seed value do?

It makes generation reproducible. The same seed combined with the same schema always produces identical output, which is useful for consistent test fixtures — change the seed to get a different dataset.

What's the difference between JSON and NDJSON output?

Standard JSON output is a single array of objects, which is what most REST APIs expect. NDJSON (newline-delimited JSON) puts one JSON object per line, which is common for log pipelines and streaming data tools.

Is there a limit to how many records I can generate?

You can generate up to 500 records at once, which is enough for most prototyping, UI testing, and fixture needs while keeping the tool fast in your browser.

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