Free Online Developer Tools for Web Developers
15 free browser-based developer tools for encoding, hashing, formatting, generating data, and testing your display. Password generator, JSON formatter, Base64 encoder, hacker typer, touchscreen test, refresh rate test, and more. No install, no account required.
Strong Password Generator
Generate cryptographically secure passwords up to 64 characters.
IP Address Lookup
Find your public IP address, location, ISP, and ASN.
SHA Hash Generator
Generate SHA-1, SHA-256, SHA-384, and SHA-512 hashes.
Base64 Encoder and Decoder
Encode text to Base64 or decode any Base64 string.
JSON Formatter and Validator
Format, validate, and minify JSON with syntax highlighting.
QR Code Generator
Generate QR codes for URLs, text, email, phone, or WiFi.
URL Encoder and Decoder
Encode or decode percent-encoded URL strings instantly.
UUID v4 Generator
Generate cryptographically random UUID v4 identifiers.
Text Encryptor
Encrypt and decrypt text with a secret key in your browser.
Test Data Generator
Generate fictional names and addresses for software testing.
Dead Pixel Test
Test your monitor for dead pixels using solid color full-screen panels.
Stuck Pixel Fixer
Fix stuck pixels by rapidly cycling colors across your screen.
Refresh Rate Test
Measure your monitor's actual refresh rate in real time.
Touchscreen Test
Test your touchscreen for dead zones and multi-touch support.
Hacker Typer
Type like a movie hacker. Any keypress outputs realistic-looking code.
15
Developer tools
SHA-512
Max hash strength
SubtleCrypto
Crypto API
100%
Client-side
Tool reference
| Tool | Category | Privacy | API / Method |
|---|---|---|---|
| Password Generator | Security | Client-only | crypto.getRandomValues() |
| SHA Hash Generator | Security | Client-only | SubtleCrypto |
| Text Encrypt | Security | Client-only | XOR cipher |
| JSON Formatter | Data | Client-only | JSON.parse/stringify |
| Base64 Encoder | Encoding | Client-only | atob / btoa |
| URL Encoder | Encoding | Client-only | encodeURIComponent |
| UUID Generator | Generate | Client-only | crypto.randomUUID() |
| QR Code Generator | Generate | Client-only | qrcode library |
| Test Data Generator | Test Data | Client-only | Random seed |
| IP Address Lookup | Network | External API | ip-api.com |
| Hacker Typer | Fun | Client-only | KeyboardEvent / Canvas |
| Touchscreen Test | Testing | Client-only | PointerEvents API |
| Refresh Rate Test | Testing | Client-only | requestAnimationFrame |
| Stuck Pixel Fixer | Display | Client-only | CSS / setInterval |
| Dead Pixel Test | Display | Client-only | Fullscreen API |
Security tools: password generator, hash, and encryption
The security tools cover three distinct use cases. The password generator creates cryptographically random passwords up to 64 characters with full control over character sets including uppercase, lowercase, numbers, and symbols. It uses crypto.getRandomValues() so no generated password follows a predictable pattern.
The SHA hash generator supports SHA-1, SHA-256, SHA-384, and SHA-512 via the browser SubtleCrypto API. Use it to hash passwords before storage verification, generate file checksums, or validate that a downloaded file matches its published hash. The text encrypt tool provides a simple XOR cipher for obfuscating strings in non-critical contexts. All three tools run entirely client-side with no data transmitted.
JSON formatter and validator for API development
The JSON formatter takes any raw or minified JSON string and returns a properly indented, human-readable version with syntax highlighting. It validates the JSON simultaneously and shows a clear parse error message with the problem location if the input is malformed. This covers the two most common JSON tasks during API development: understanding a large response and debugging a payload that is failing to parse.
The formatter handles deeply nested objects, large arrays, escaped characters, and Unicode strings. Paste the JSON directly from your browser DevTools network panel, your API client, or a log file. The formatted output can be copied in one click. All processing uses the browser's native JSON.parse and JSON.stringify so no JSON leaves your machine.
Encoding tools: Base64, URL encoder, and QR code generator
The Base64 encoder and decoder converts text or binary strings to Base64 and back using the browser's native btoa and atob functions. Common use cases include encoding API credentials for Authorization headers, embedding small images as data URIs, and encoding binary payloads for JSON transport.
The URL encoder converts unsafe characters to percent-encoded format using encodeURIComponent and decodes them back. Use it for query string parameters, form submissions, and path segments that contain special characters. The QR code generator converts any URL or string into a downloadable QR code image, useful for linking printed materials to web pages and sharing URLs without typing.
UUID generator and test data tools
The UUID v4 generator produces cryptographically random universally unique identifiers using crypto.randomUUID(). UUIDs generated this way are suitable for database primary keys, distributed system record identifiers, session tokens, and any context where uniqueness across systems must be guaranteed without a central coordinator.
The test data generator creates realistic fake identity records including names, email addresses, phone numbers, and addresses. Use it to seed development databases, populate UI with realistic-looking data during prototyping, and generate form input for QA testing without using real personal data. All generated records are random and fictional with no connection to real individuals.
Browser-based developer tools: no install, no account
Browser-based developer tools eliminate dependency management, version conflicts, and installation overhead. Opening a browser tab is faster than launching any desktop application, and these tools are bookmarkable and accessible from any machine including ones where software installation is restricted. Every tool on this page works in Chrome, Firefox, Safari, and Edge on desktop and mobile without any extension or plugin.
The one exception to fully client-side processing is the IP address lookup tool, which makes a request to an external geolocation API to resolve your public IP and return location metadata. All other tools process data locally: nothing you enter into a password, hash, encoder, formatter, or generator field is transmitted to any server or stored in any log.
Frequently asked questions
All processing runs entirely in your browser. No passwords, hashes, encoded strings, JSON, or generated values are sent to any server. The SHA hash generator uses the browser SubtleCrypto API directly. The Base64 encoder, URL encoder, and JSON formatter use native browser functions. The only exception is the IP address lookup tool, which makes a request to an external geolocation API to resolve your public IP.
Yes. Both the password generator and UUID v4 generator use the browser crypto.getRandomValues() API, which draws entropy from system-level sources. This produces values that pass cryptographic randomness tests and are suitable for production use in authentication systems, database primary keys, and session token generation.
The SHA hash generator supports SHA-1, SHA-256, SHA-384, and SHA-512 via the browser SubtleCrypto API. SHA-256 and SHA-512 are the recommended choices for modern security applications. SHA-1 is included for legacy compatibility and verification use cases only. All hashing runs client-side with no data transmitted.
Yes. The JSON formatter and validator handles large JSON payloads. Paste the raw JSON from any API response, and the tool formats it with proper indentation, highlights syntax, and flags any parse errors with a clear error message. It works for minified JSON, nested objects, and arrays of any depth.
Base64 encoding converts binary data or text into a string of ASCII characters using a 64-character alphabet. It is used for embedding binary data in JSON, HTML, and email. URL encoding converts characters that are not safe in a URL into percent-encoded equivalents, such as spaces becoming %20. Use the Base64 encoder for data payloads and the URL encoder for query string parameters and path segments.
Yes. All tools on this page are responsive and usable on phone and tablet. Input fields, copy buttons, and output areas adapt to any screen width. The JSON formatter and Base64 tools handle large text inputs on mobile without performance issues. No app download is required.
The QR code generator converts any URL, text, or string into a scannable QR code image. Common uses include linking physical materials to web pages, sharing Wi-Fi credentials, embedding contact details, and adding quick-access links to printed documents. The QR code is generated entirely in the browser and can be downloaded as an image.
The test data generator creates realistic fake identity records including names, email addresses, phone numbers, addresses, and other common form fields. It is designed for populating test databases, seeding development environments, and UI testing without using real personal data. All generated data is random and fictional.
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