What is Base64 encoding?

Base64 is a way to represent binary or text data using only 64 printable characters (A–Z, a–z, 0–9, +, /). It's commonly used to safely transmit data in systems that only support plain text — like email bodies, JSON payloads, and HTTP headers. It's an encoding scheme, not encryption, so it does not hide or secure your data.

Is this Base64 tool safe to use for sensitive data?

Yes. This tool runs entirely in your browser using JavaScript. Nothing you type or paste is ever sent to a server. Your data never leaves your device. That said, remember that Base64 is not encryption — anyone with the encoded string can decode it just as easily.

Why does my Base64 decoded output look like garbled text?

If you're decoding something that was originally binary data — like an image, PDF, or compressed file — the output will look like garbled characters. That's expected. Base64 isn't limited to text; it's often used to encode binary files. If you're expecting readable text, double-check that the original content was a plain text string before it was encoded.

How do I encode an image to Base64 for use in HTML or CSS?

To use an image as a Base64 data URI in HTML or CSS, you need to encode the raw binary of the image file. This tool supports text-based encoding directly. For binary files like images, use the file upload option (if available) or encode the file contents. The resulting string can be used as: src="data:image/png;base64,YOUR_STRING_HERE" in an img tag.

Can I use this tool to decode Base64 strings in JWT tokens?

Yes, partially. A JWT has three parts separated by dots — header, payload, and signature. The header and payload are Base64URL encoded (a variant of standard Base64 using - and _ instead of + and /). You can paste either part into this decoder to read the JSON inside. Note that this tool decodes the content only — it does not verify the JWT signature.

⚡ Speed Up Workflow⚡ Workflow

Base64 Encoder & Decoder

Source Stream

Resulting Payload

Awaiting transformation...

Encode or Decode Any String Online

You've got a Base64 string staring at you — something likeSGvsbG8gV29ybGQ= — and you just need to know what it says. Or you're building an API request and need to encode your credentials before dropping them into an Authorization header. Either way, you don't want to open a terminal or pull up a REPL just to run two lines of code.

This tool handles both directions: paste plain text and get Base64 out, or paste a Base64 string and get readable text back. It's free, requires no account, and runs entirely in your browser — your input never touches a server.

Quick Overview

Encode any text to Base64 instantly with real-time results.
Decode any Base64 string back to plain text in one step.
Works fully in your browser — no data is ever sent to a server.
Handles standard and URL-safe Base64 (Base64URL) for JWTs.
Copy your result in one click, ready for your code or API.

Real-World Use Case

Priya is a backend developer integrating a third-party REST API that uses HTTP Basic Auth. The API docs say to base64-encode the string clientId:clientSecret and include it in the Authorization header. She opens Utilx, pastes my_client_id:my_secret_key into the encoder, copies the output, and drops it straight into her Postman request header. Done in under 20 seconds, no context switch.

Private & Secure

All encoding and decoding happens in JavaScript on your device. Nothing is sent to any server — your data stays yours. This makes it safe for processing sensitive strings or tokens.

LOCAL COMPUTE PROTOCOL

Instant Output

Results update as you type — no submit button, no page reload.

100% Free

No account required. Open the page and start using it immediately.

Browser-Based

Runs entirely in JavaScript. No data is sent to any server.

URL-Safe Support

Handles both standard and URL-safe Base64 (Base64URL) formats.

When to Use This Tool

API Authentication

If you're setting up HTTP Basic Authentication, use this tool to encode your username:password pair before adding it to your Authorization: Basic header.

JWT Inspection

If you receive a JWT and want to read the payload, paste the middle segment here to decode it and inspect the claims without needing a separate JWT tool.

Data URIs

If you're embedding a small icon or SVG directly in CSS or HTML as a data URI, encode the raw content here to get the Base64 string you need.

4-Step Workflow

PICK DIRECTION

Choose Encode to go from plain text → Base64, or Decode to go from Base64 → plain text.

PASTE INPUT

Drop your text or Base64 string into the input box. Paste from clipboard or type directly.

INSTANT RESULT

Output appears as you type — no submit button, no waiting. Updates in real time.

COPY & MOVE ON

Hit the Copy button to grab the output and use it in your code, API call, or document.

Related Encoding Tools

URL Encoder

URL encoder for safe transport of special characters in parameters.

JSON Formatter

JSON formatter for API responses — clean up your decoded payloads.

Regex Tester

Bulk string replacement and pattern matching for encoded strings.

Privacy Statement

This tool runs 100% in your browser — no data is sent to any server, logged, or stored anywhere. Your input never leaves your device.

Browser Compatibility

Works in all modern browsers — Chrome, Firefox, Safari, and Edge — on desktop and mobile. No installation required.

FAQs

Base64 is a way to represent binary or text data using only 64 printable characters — the letters A–Z and a–z, digits 0–9, and the symbols + and /. It's widely used when you need to send data through channels that only handle text, like email, JSON payloads, or HTTP headers. One important thing to know: Base64 is an encoding scheme, not encryption. Anyone with the encoded string can decode it instantly. It's about compatibility, not security.

Data & Docs