Free Developer Tools
JSON formatter, data converter, JWT decoder, cron generator, QR codes, password generator, timestamp converter, and more — all free, all browser-based. Your code and data never leave your device.
10
Free Tools
100%
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Signup Needed
🗄️ Data & Format Tools
MD5 / SHA Hash Generator
Client-side SHA-256 & MD5 hashing
Compute secure MD5, SHA-1, SHA-256, and SHA-512 checksums for text or files. 100% client-side privacy using the native Web Crypto API. Zero server uploads.
- Verify file integrity
- Hash API payloads
- Test password salting mechanisms
UUID / GUID Generator
Bulk v4 & v1 generator
Instantly generate bulk UUIDs (Universally Unique Identifiers) and GUIDs. Supports random (v4) and timestamp (v1) formats. 100% client-side data privacy.
- Generate database keys
- Create API testing tokens
- Mock massive datasets
URL Encoder / Decoder
Safely parse and format URLs
Instantly encode or decode full URLs and query strings. Safely parse percent-encoded links, encodeURI, and encodeURIComponent. 100% client-side data privacy.
- Format API requests safely
- Extract readable JSON from callback links
- Clean broken URLs
CSS Gradient Generator
Live preview linear, radial & conic gradients
Create stunning CSS gradients instantly. Live preview and generate code for linear, radial, and conic backgrounds. Copy-ready CSS, no upload needed.
- Design modern UI backgrounds
- Replace heavy background images
- Generate cross-browser CSS
JSON Formatter & Validator
Beautify, minify & validate JSON
Paste messy JSON, get clean, indented output instantly. Real-time error detection with precise line and column numbers. Minify for production or beautify for debugging.
- Debug malformed API responses
- Format config files
- Prepare JSON for production
Data Converter & Formatter
Convert JSON ↔ CSV ↔ XML ↔ YAML
The all-in-one data playground. Convert between all major formats, run JSONPath queries, view data as tree or table, fetch from URLs, and export charts.
- Transform API response to CSV
- Extract fields with JSONPath
- Migrate data between formats
Data Visualization Builder
Build interactive charts from CSV data
Upload CSV or paste data and instantly build interactive bar, line, pie, and scatter charts. Filter, aggregate, customise colors, and download as PNG or PDF.
- Visualise sales or traffic data
- Build presentation charts
- Explore CSV datasets
🔐 Security & Authentication
JWT Decoder & Analyzer
Decode, verify & audit JWT tokens
Paste any JWT to instantly decode the header, payload, and signature. Checks expiration, detects security pitfalls (like the "none" algorithm), and verifies HS256 signatures.
- Debug auth tokens from any API
- Validate JWT expiry (exp)
- Detect security vulnerabilities
Password Generator
Cryptographically strong passwords
Generate secure, random passwords with custom length (up to 128 chars), character sets (uppercase, lowercase, numbers, symbols), strength indicator, and copy to clipboard.
- Generate API keys and secrets
- Create server admin passwords
- Bulk password generation
⏱️ Scheduling & Time
Cron Job Generator & Explainer
Build & parse cron expressions visually
Create cron schedules with a visual editor that translates every expression into plain English in real time. Parse existing cron strings, use presets, and generate full crontab commands.
- Schedule automated backups
- Set up recurring maintenance jobs
- Debug existing cron strings
Unix Timestamp Converter
Epoch to date — auto-detects s/ms/μs/ns
Convert Unix timestamps to human-readable dates and back. Auto-detects seconds, milliseconds, microseconds, or nanoseconds. Batch mode, all IANA timezones, start/end of day ranges.
- Debug server log timestamps
- Work with API date fields
- Convert database time values
🛠️ Utilities & Design
QR Code Generator
QR codes for URL, WiFi, SMS, email & more
Create customizable QR codes for URLs, plain text, email addresses, phone numbers, SMS, and WiFi credentials. Custom colors, error correction, and multiple download formats.
- Add website link to printed materials
- Share WiFi credentials
- Create contactless business cards
Lorem Ipsum Generator
Placeholder text for any design or format
Generate classic or themed placeholder text as paragraphs, sentences, words, or HTML lists. Multiple languages, custom themes, and export as plain text, HTML, JSON, or Markdown.
- Fill UI mockups and wireframes
- Test CMS content rendering
- Create design prototypes
CSS Neumorphism Generator
Generate Soft UI box-shadow CSS instantly
Build neumorphic (Soft UI) designs with a live preview. Adjust size, radius, shadow distance, blur, and color. Generate the CSS code for extruded and pressed states with one click.
- Design soft UI cards and buttons
- Build modern dashboard components
- Learn neumorphism CSS
Which Tool Should I Use?
Match your task to the right tool:
| I need to… | Example | Use this tool |
|---|---|---|
| Format or validate messy JSON | API response is unreadable | JSON Formatter & Validator |
| Convert JSON to CSV (or vice versa) | Transform REST response to spreadsheet | Data Converter & Formatter |
| Decode or audit a JWT token | Check claims, exp date, and security | JWT Decoder & Analyzer |
| Write or debug a cron expression | "Run every Monday at 9 AM" | Cron Job Generator |
| Create a QR code for a link or WiFi | Add to a print flyer or business card | QR Code Generator |
| Generate a strong, random password | New DB or server admin account | Password Generator |
| Convert a Unix timestamp to a date | Debug a server log or API response | Timestamp Converter |
| Get placeholder text for a mockup | Fill a Next.js layout wireframe | Lorem Ipsum Generator |
| Build a chart from CSV or JSON data | Visualise monthly sales numbers | Data Visualization Builder |
| Generate Soft UI / neumorphic CSS | Design a pressed button effect | CSS Neumorphism Generator |
Cron Expression Syntax Reference
A cron expression has five space-separated fields. Each field controls a time unit:
| Field | Position | Allowed Values | Special Characters |
|---|---|---|---|
| Minute | 1st | 0–59 | * , - / |
| Hour | 2nd | 0–23 | * , - / |
| Day of Month | 3rd | 1–31 | * , - / ? L W |
| Month | 4th | 1–12 or JAN–DEC | * , - / |
| Day of Week | 5th | 0–7 or SUN–SAT | * , - / ? L # |
Common Cron Examples
* * * * *Every minute0 * * * *Every hour (at :00)0 9 * * *Every day at 9:00 AM0 9 * * 1Every Monday at 9:00 AM0 0 * * *Every day at midnight0 0 1 * *First day of every month*/15 * * * *Every 15 minutes0 9-17 * * 1-5Every hour, 9 AM–5 PM, Mon–FriJWT Structure Reference
A JWT consists of three base64url-encoded sections separated by dots:
Header
{ "alg": "HS256", "typ": "JWT" }Signing algorithm and token type
Payload
{ "sub": "123", "name": "John", "iat": 1600000000 }Claims: subject, name, issued-at, expiry, etc.
Signature
HMACSHA256(base64(header) + "." + base64(payload), secret)Verifies the token was not tampered with
| Claim | Name | Description |
|---|---|---|
| sub | Subject | Identifies the principal (user ID, email, etc.) |
| iss | Issuer | Who created and signed the token |
| aud | Audience | Who the token is intended for |
| exp | Expiration | Unix timestamp after which the token is invalid |
| iat | Issued At | Unix timestamp when the token was created |
| nbf | Not Before | Token is invalid before this Unix timestamp |
| jti | JWT ID | Unique identifier for this token (prevents reuse) |
JSON vs CSV vs XML vs YAML — When to Use Each
Use the Data Converter to switch between any of these formats instantly.
| Format | Best For | Readable by Humans | Supports Nesting | Common Use |
|---|---|---|---|---|
| JSON | APIs & web apps | ✅ Yes | ✅ Yes | REST APIs, config files, databases |
| CSV | Tabular / flat data | ✅ Yes | ❌ No | Spreadsheets, reports, data exports |
| XML | Document / enterprise | ⚠️ Verbose | ✅ Yes | SOAP APIs, RSS feeds, legacy systems |
| YAML | Config files & DevOps | ✅ Very | ✅ Yes | Docker Compose, GitHub Actions, Ansible |
Why Use Texterfly Developer Tools?
Completely Private
All processing runs in your browser. Your JSON, JWT tokens, passwords, and data are never sent to any server or stored anywhere — safe for sensitive credentials and internal data.
Instant & No-Install
No download, no extension, no account. Open any tool and get results in under a second. Works on Windows, macOS, Linux, iOS, and Android.
Developer-Grade Output
Tools are built for real-world development workflows — not just quick demos. JWT security audits, JSONPath queries, batch timestamp conversion, and export to CSV/PDF.
Frequently Asked Questions
What developer tools does Texterfly offer?
Texterfly offers 10 free developer tools: JSON Formatter & Validator, Data Converter (JSON/CSV/XML/YAML), JWT Decoder & Analyzer, Cron Job Generator, QR Code Generator, Password Generator, Unix Timestamp Converter, Lorem Ipsum Generator, Interactive Data Visualization Builder, and CSS Neumorphism Generator. All are browser-based with no signup required.
How do I format and validate JSON online?
Paste your JSON into the JSON Formatter & Validator. It detects syntax errors with precise line and column numbers, beautifies the output with proper indentation, and offers minification for production. 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 Data Converter & Formatter. Paste your source data, select the output format (JSON, CSV, XML, or YAML), and the conversion is instant. You can also run JSONPath queries to extract specific fields before converting, and download the result directly.
How do I decode a JWT token?
Paste your JWT into the JWT Decoder & Analyzer. The tool splits it into header, payload, and signature, decodes the base64url content, checks the exp (expiration) claim, and flags common security issues like the none algorithm vulnerability. For HS256 tokens you can enter a secret to verify the signature.
How do I write a cron expression?
Cron expressions have five fields: minute (0–59), hour (0–23), day of month (1–31), month (1–12), day of week (0–7). Examples: "0 9 * * 1" = every Monday at 9 AM; "0 0 * * *" = daily at midnight; "*/15 * * * *" = every 15 minutes. Use the Cron Job Generator to build these visually with real-time English translation.
What makes a password strong and secure?
A strong password has at least 16 characters, mixes uppercase, lowercase, numbers, and symbols, avoids dictionary words, and is unique per account. The Password Generator creates cryptographically random passwords using your browser's secure random API and shows an entropy score so you know exactly how strong each password is.
What is a Unix timestamp?
A Unix timestamp is the number of seconds since January 1, 1970, 00:00:00 UTC. A 10-digit value is seconds; 13 digits is milliseconds; 16 is microseconds; 19 is nanoseconds. The Timestamp Converter auto-detects the unit and converts to/from any date and timezone.
What is the structure of a JWT?
A JWT (JSON Web Token) has three base64url-encoded parts separated by dots: Header.Payload.Signature. The Header specifies the algorithm (e.g. HS256). The Payload contains claims: sub (subject), exp (expiration), iat (issued at), iss (issuer), and any custom claims. The Signature verifies the token was not tampered with.
What is neumorphism in CSS?
Neumorphism (Soft UI) uses two box shadows — one light, one dark — on an element whose background matches its container, creating a soft raised or pressed 3D appearance. The CSS Neumorphism Generator produces the exact box-shadow code for any color, size, radius, and depth with a live preview.
Are these developer tools free?
Yes. All 10 tools are 100% free with no registration, subscription, or payment required.
Is my code and data private?
Yes. All processing runs entirely in your browser. 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 internal data.
Can I use these tools for commercial projects?
Yes. All Texterfly developer tools are free for personal and commercial use with no licensing restrictions on the output.