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.

Is this password generator cryptographically secure?

Yes. This tool uses the Web Crypto API (crypto.getRandomValues), the same standard used by password managers and security software. It does not use Math.random(), which is not suitable for cryptographic purposes.

Are my generated passwords stored or sent anywhere?

No. All password generation runs entirely in your browser using JavaScript. Nothing is ever transmitted to Texterfly's servers. You can confirm this by disconnecting from the internet after the page loads — the generator still works.

What is password entropy and how many bits do I need?

Entropy (measured in bits) quantifies how hard a password is to guess by brute force. Each additional bit doubles the number of guesses required. For most accounts, 60–80 bits is sufficient. For email, banking, and password manager master passwords, aim for 100–128+ bits.

What is a passphrase and why is it more secure?

A passphrase is a sequence of random words (e.g., "tiger-blanket-river-dance"). Five random words from a large wordlist yield ~65 bits of entropy — equivalent to a 12-character complex password — while being far easier to remember. This is the principle behind the NIST-recommended diceware method.

What does "exclude similar characters" mean?

Characters like l (lowercase L), 1 (one), I (capital i), O (capital o), and 0 (zero) look identical in many fonts. Enabling this option removes them from the character pool so your password is easier to read and type manually without errors.

Can I generate multiple passwords at once?

Yes. Use the Bulk Generate tab to create up to 20 passwords at once with your current settings. You can copy them all to your clipboard in one click.

Back to Developer Tools

Password Generator

Generate cryptographically secure passwords and passphrases instantly — free, private, and 100% browser-based.

Click generate to get a password

Quick Presets

Length

43264128

Character Sets

UppercaseA–Z

Lowercasea–z

Numbers0–9

Symbols!@#$%^&*

Exclusions

No Similarl, 1, I, O, 0

No Ambiguous{}[]()\/;:.,'

100% Private & Cryptographically Secure

Uses crypto.getRandomValues() — the same standard as password managers. Nothing is sent to any server. Disconnect the internet after load and this tool still works.

Support Our Free Tools

If you find this calculator helpful, please consider supporting our work. Your contribution helps us build and maintain these free tools for everyone.

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Free Password Generator — Cryptographically Secure, No Sign-Up

This tool uses the browser's Web Crypto API (crypto.getRandomValues) to generate passwords — the same standard used by professional password managers like Bitwarden and 1Password. Every character is selected from a truly random source, making the output impossible to predict. Nothing is stored, logged, or transmitted.

Whether you need a quick 6-digit PIN, a complex 32-character password for a server, or a memorable diceware passphrase, this generator covers all use cases with one clean tool.

The Science of Password Security

What is password entropy?

Entropy (measured in bits) quantifies how hard a password is to crack by brute force. Every additional bit doubles the number of guesses required. At 1 trillion guesses per second — a realistic modern GPU cluster — a 60-bit password would take about 13 days. A 128-bit password would take longer than the age of the universe.

< 40

Very Weak

Cracked in seconds

40–60

Weak

Hours to days

60–100

Good

Years to centuries

128+

Excellent

Computationally infeasible

Length vs. complexity — what wins?

Length beats complexity every time. A 20-character lowercase-only password has more entropy than a 10-character password using all character types. This is why NIST now recommends prioritizing length and has dropped mandatory complexity rules in its 2024 guidelines.

Tr0ub4dor&3Hard to type, easy to crack44 bits

correcthorsebatterystapleXKCD classic — far stronger77 bits

tiger-blanket-river-dance-north5 random words + hyphens97 bits

Quick Guide — Which Preset to Use

🔐

Max Security (32 chars)

Password managers, SSH keys, server credentials, root passwords

~200 bits

🌐

Readable (16 chars)

Sites that don't allow symbols, or that you'll need to type manually

~90 bits

📶

WiFi Password (20 chars)

Router passwords you'll type on phones and TVs — readable but strong

~110 bits

🔢

PIN (6 digits)

Phone lock screens, ATM PINs, door codes

~20 bits

🧠

Passphrase (5+ words)

Master passwords, email accounts, anything you need to memorize

~65+ bits

📋

Bulk Generate

Provisioning accounts, testing systems, generating API keys in quantity

Your settings

Frequently Asked Questions

Is this password generator truly cryptographically secure?

Yes. It uses crypto.getRandomValues() — the Web Crypto API built into every modern browser. This is a cryptographically secure pseudo-random number generator (CSPRNG), unlike Math.random() which is deterministic and unsuitable for security applications. The output is indistinguishable from true randomness.

Are my passwords stored or sent to a server?

Never. All generation happens in your browser using client-side JavaScript. No data is transmitted. You can verify this by opening browser DevTools → Network tab while generating a password — you will see zero network requests.

How long should my password be in 2025?

NIST SP 800-63B (2024 revision) recommends a minimum of 15 characters for standard accounts and 20+ for high-value targets. For anything you store in a password manager (which is everything, ideally), use 20–32 characters. For master passwords you must memorize, use a 5–6 word passphrase instead.

What is the diceware / passphrase method?

Diceware was invented by Arnold Reinhold in 1995. You roll physical dice to pick words from a numbered wordlist, creating a passphrase where every word is independently random. Our passphrase mode uses the same principle digitally — each word is selected using crypto.getRandomValues() from our wordlist, giving each word equal, independent probability.

Why should I use a password manager?

The only secure way to use unique, strong passwords for every account is to not memorize them — let a password manager do it. Recommended options: Bitwarden (free, open-source), 1Password (paid, excellent UX), KeePassXC (offline, open-source). Use this generator to create the passwords, save them in the manager, and remember only one strong master passphrase.

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