What is Base64 encoding used for?

Base64 encoding converts binary data into ASCII text format. It's commonly used for embedding images in HTML/CSS (data URIs), encoding API authentication tokens, transmitting data through email (MIME encoding), and encoding JWT token payloads. Polymorpher's Base64 tool supports both encode and decode with UTF-8 support.

What is a JWT token and how do I decode it?

A JSON Web Token (JWT) is a compact, URL-safe token used for authentication in APIs and web applications. It consists of three Base64-encoded parts: header, payload, and signature. Polymorpher's JWT Decoder lets you paste any JWT to instantly inspect the algorithm, claims, expiration time, and custom fields without needing the signing secret.

How do I convert HEX colors to RGB?

Polymorpher's Color Converter instantly converts HEX colors (like #FF5733) to RGB format (rgb(255, 87, 51)) and HSL format. It also generates ready-to-use CSS custom properties and Tailwind CSS classes. Simply paste any color in HEX, RGB, or HSL format and get all conversions with a live color preview.

Polymorpher — Free Online Developer Tools

JSON to Code Classes Converter

Convert JSON to C# classes, cast JSON to Java classes, transform JSON to Python dataclasses, generate TypeScript interfaces from JSON, convert JSON to Go structs, Kotlin data classes, Dart models, Ruby classes, Swift Codable structs, and Rust structs. Free online JSON to code converter with reverse transformation support.

SQL to Code Classes Converter

Transform SQL CREATE TABLE statements to C# EF Core entities, convert SQL to POCO classes, cast SQL schemas to C# Records. Free online SQL to class generator with bi-directional conversion.

Code Beautifier & Formatter

Beautify and format JSON, XML, SQL, CSS, HTML, and C# code online. Auto-detects format and applies proper indentation. Reverse transform minifies code for production. Free code formatter for developers.

Unit Converter

Convert between metric and US imperial units. Length, weight, temperature, area, volume, speed, and pressure converter with scientific precision. Free online measurement converter.

Base64 Encoder & Decoder

Encode text to Base64 or decode Base64 strings back to plain text instantly. Essential for APIs, JWT tokens, email encoding, data URIs, and authentication headers. Free online Base64 converter.

URL Encoder & Decoder

Encode text for safe URL usage with percent-encoding or decode URL-encoded strings. Perfect for query strings, form data, API parameters, and HTTP requests. Free URL encoder and decoder tool.

Hash Generator — MD5, SHA256, SHA512 & HMAC

Generate cryptographic hash digests using MD5, SHA1, SHA256, SHA384, SHA512 algorithms. Supports HMAC with custom secret keys for API authentication and data integrity. Free online hash generator.

JWT Token Decoder

Decode JSON Web Tokens to inspect header, payload, claims, and expiration. Debug OAuth2 flows and API authentication tokens instantly. Free JWT decoder — no signing secret required.

Color Converter — HEX, RGB & HSL

Convert colors between HEX, RGB, and HSL formats with live preview. Get CSS custom properties and Tailwind CSS classes. Free online color converter for designers and developers.

Regex Tester & Pattern Matcher

Test regular expressions against any text and see all matches with capture groups. Built-in regex cheat sheet included. Supports .NET regex flavor. Free online regex tester.

DateTime Converter — Unix Epoch & ISO 8601

Convert between Unix timestamps, ISO 8601, RFC 2822, and human-readable date formats. Supports seconds, milliseconds, and relative time output. Free online epoch converter for developers.

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Polymorpher

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Convert, transform, beautify & decode — all in one place.

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Select a tool from the sidebar to get started, or explore our free developer utilities.

Free Online Developer Tools

10 professional-grade utilities — zero sign-up, zero data storage. Every transformation is stateless and private.

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JSON to Code Classes

Convert JSON to strongly-typed classes in C#, Java, Python, TypeScript, Go, Kotlin, Dart, Ruby, Swift, and Rust. Supports nested objects, arrays, and nullable types. Reverse transform generates JSON from code.

🗃️

SQL to Code Classes

Transform SQL CREATE TABLE statements into EF Core entities, POCO classes, or C# Records. Auto-generates [Key], [Required], [MaxLength] data annotations with correct type mapping.

✨

Code Beautifier & Formatter

Beautify and format minified JSON and C# code instantly. Reverse transform minifies formatted code back into compact single-line output for production use.

📐

Unit Converter

Convert between 50+ measurement units across Length, Area, Weight, Volume, Temperature, Speed, and Data categories. Supports metric (SI) and US Imperial systems with 15-digit precision.

🔐

Base64 Encoder & Decoder

Encode text to Base64 or decode Base64 strings back to plain text. Essential for APIs, JWT tokens, email encoding (MIME), data URIs, and HTTP authentication headers. Full UTF-8 support.

🔗

URL Encoder & Decoder

Encode text for safe URL usage with percent-encoding or decode URL-encoded strings. Handles query strings, form data, API parameters, and all special characters including Unicode.

🛡️

Hash Generator

Generate cryptographic hash digests using MD5, SHA1, SHA256, SHA384, SHA512. Supports HMAC with secret keys for API authentication, webhook verification, and data integrity checks.

🔑

JWT Token Decoder

Decode JSON Web Tokens to inspect header and payload claims without the signing secret. Debug OAuth2 flows, verify token expiration, and understand JWT structure instantly.

🎨

Color Converter

Convert colors between HEX, RGB, and HSL formats with live preview. Auto-detects input format and outputs CSS variables and Tailwind CSS classes ready for your codebase.

🔍

Regex Tester

Test regular expressions against text with match highlighting, capture groups, and detailed results. Supports .NET regex flavor including lookaheads, lookbehinds, and named groups.

How It Works

Three simple steps — paste, transform, copy. No sign-up, no installation, no data stored.

Paste Your Input

Select a tool from the sidebar and paste your text, code, or data into the input editor. Polymorpher auto-detects the format.

Transform Instantly

Click "Transform" — the result appears in milliseconds. Most tools support reverse transform with the swap button.

Copy & Use

One-click copy puts the result on your clipboard. Your input is processed in real-time and immediately discarded — zero data retention.

Frequently Asked Questions

Is Polymorpher really free?

Yes, 100% free with no sign-up, no trial period, and no premium tier. All 10 tools are available without any account or payment.

Is my data safe? Do you store anything?

Polymorpher is fully stateless. Your code, JSON, SQL, tokens, and all other input are processed in real-time and immediately discarded. We have no database — nothing is stored, logged, or tracked. Your data never touches a disk.

What programming languages are supported for JSON to Code conversion?

Polymorpher supports 10 languages: C#, Java, Python, TypeScript, Go, Kotlin, Dart, Ruby, Swift, and Rust. Each generates idiomatic code with proper naming conventions, type inference, and nested class support.

How does the hash generator work? Does it support HMAC?

The hash generator supports MD5, SHA1, SHA256, SHA384, and SHA512 algorithms. You can select a specific algorithm or generate all digests at once. HMAC mode is supported — enter a secret key to produce authenticated message digests used for API signatures and webhook verification.

Can I use Polymorpher offline?

Polymorpher requires an internet connection since transformations are processed by our .NET 10 API for accuracy and speed. However, the processing is stateless — each request is independent and nothing is cached server-side.

What is the reverse transform / swap feature?

Most tools support bi-directional conversion. For example, Base64 encode ↔ decode, URL encode ↔ decode, JSON to C# ↔ C# to JSON. Click the "Swap" button to reverse the transform direction instantly.

From Our Blog

Guides, tutorials, and deep dives for developers.

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Polymorpher guides are reviewed for technical accuracy, updated when behavior changes, and include practical examples intended for real developer workflows.

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Polymorpher

⚡ All Tools

Did You Know?

Welcome to Polymorpher

Unit Converter

About this Tool

Free Online Developer Tools

JSON to Code Classes

SQL to Code Classes

Code Beautifier & Formatter

Unit Converter

Base64 Encoder & Decoder

URL Encoder & Decoder

Hash Generator

JWT Token Decoder

Color Converter

Regex Tester

How It Works

Paste Your Input

Transform Instantly

Copy & Use

Frequently Asked Questions

From Our Blog

How to Convert JSON to C# Classes

SHA256 vs MD5: Which Hash Algorithm?

Understanding JWT Tokens

10 Regex Patterns Every Developer Should Know

Base64 Encoding Explained

JSON to Python Dataclass

Our Content Standards

Polymorpher

⚡ All Tools

Did You Know?

Welcome to Polymorpher

Unit Converter

About this Tool

Free Online Developer Tools

JSON to Code Classes

SQL to Code Classes

Code Beautifier & Formatter

Unit Converter

Base64 Encoder & Decoder

URL Encoder & Decoder

Hash Generator

JWT Token Decoder

Color Converter

Regex Tester

How It Works

Paste Your Input

Transform Instantly

Copy & Use

Frequently Asked Questions

From Our Blog

How to Convert JSON to C# Classes

SHA256 vs MD5: Which Hash Algorithm?

Understanding JWT Tokens

10 Regex Patterns Every Developer Should Know

Base64 Encoding Explained

JSON to Python Dataclass

Our Content Standards

Metric System