Developer Tool

Base64 Encode and Decode

Securely encode plain text into Base64 format or decode Base64 strings back into readable text. Everything happens instantly in your browser.

Upload File to Encode

Processing...

Length:

Security & Encoding Logic

This tool utilizes strictly client-side JavaScript APIs to execute zero-latency operations. We use native browser UTF-8 conversion mapping to ensure complete compatibility with emojis and international characters.

Completely Secure

Everything runs instantly in the browser. No text data is ever transferred across the internet or stored on our databases.

Developer Friendly

Easily swap inputs and outputs using the toggle button to test configurations or decode tricky OAuth tokens on the fly.

Related Tools

JSON Formatter

Format & validate JSON data

Markdown to HTML

Render Markdown as clean HTML

Password Generator

Create secure passwords instantly

How to use the Base64 Tool

Encoding Text

1 Ensure the toggle at the top is set to Encode Text.
2 Type or paste your normal readable text into the top Plain Text Input box.
3 The tool will instantly convert your text to a secure Base64 string in the bottom Base64 Output box.
4 Click the Copy Result button to save your encoded string to your clipboard.

Decoding Base64

1 Click the Decode Base64 toggle button at the top to switch modes.
2 Paste your formatted Base64 string (e.g., SGVsbG8=) into the top box.
3 The tool will instantly reverse the encoding, revealing the original text in the bottom box.
4 If your string is malformed or invalid, a warning tag will dynamically appear.

Pro Tip: Hover over the output box and click the floating "Swap" arrows to instantly throw your result back to the top and automatically flip the mode so you can test strings back-and-forth!

Base64 Encoding - How Files Travel Through APIs

Base64 converts binary data into text-safe characters so data can move through systems designed for text transport.

It is widely used in APIs, email MIME payloads, JWT segments, and data URIs for inline assets.

This tool provides quick encode/decode workflows in-browser for safer debugging and developer productivity.

💻 Developer's Guide to Base64

Use Cases

Best for text-safe transport, not for storage optimization or security.

Size Overhead

Base64 increases payload size by roughly 33 percent, so avoid it for very large files when possible.

Not Encryption

Base64 is reversible encoding. Treat sensitive data with proper encryption standards.

URL-Safe Variant

For URLs and tokens, use Base64URL variant to avoid plus, slash, and padding issues.

Base64 Encoder and Decoder quick facts

Supports:

Text, files, Unicode and URL-safe Base64

Size:

Base64 output is about one third larger than the original

Not:

A form of encryption, so it does not protect secrets

How to use the Base64 Encoder and Decoder

Choose Encode or Decode.
Paste your text or upload a file.
Copy or download the result.

What Base64 is

Base64 represents binary data using 64 printable characters so it can travel through systems built for text, such as email and JSON. The output is about one third larger than the input.

Not encryption

Base64 offers no security. Anyone can decode it, so do not use it to hide passwords or personal data.

URL-safe variant

The URL-safe form replaces + and / with - and _ and often drops the = padding. It is used in JWTs and in URLs.

Frequently asked questions about the Base64 Encoder and Decoder

What is Base64 encoding?

Base64 is a binary-to-text encoding scheme that converts binary data into a set of 64 printable ASCII characters. It is commonly used to embed images in HTML/CSS, transmit data in URLs, and encode email attachments.

Is Base64 the same as encryption?

No. Base64 is an encoding scheme, not encryption. It can be easily decoded by anyone. Never use Base64 to protect sensitive data.

Why would I use Base64?

Common uses include embedding images in CSS/HTML data URIs, encoding binary data for JSON APIs, encoding email attachments (MIME), and passing data in URLs safely.

Is my data safe?

Yes. All encoding and decoding runs in your browser using JavaScript, and no data is sent to any server. Remember that Base64 is not encryption, though: anyone who sees the encoded text can decode it, so never use it to hide secrets.

Is this tool free?

Yes. The Base64 Tool is free to use with no sign-up and no limit on use. It encodes and decodes text and files in your browser, so what you paste is not sent to or stored on our servers.

Why does Base64 increase data size?

Base64 turns binary data into a limited set of text characters, using four characters for every three bytes. That makes the result about one third larger than the original. The trade-off is that the text is safe to send through systems that only handle plain text.

What is Base64URL?

Base64URL is a URL-safe version of Base64 that replaces the plus and slash characters with a hyphen and an underscore and usually drops the equals-sign padding. It is used in web addresses and in JWTs. This decoder accepts both the standard and URL-safe forms.

Can I embed images directly with Base64?

Yes, using data URIs in HTML or CSS. This suits very small images, because it saves a request, but larger images make the page heavier and cannot be cached separately. For bigger images, serve a normal image file instead.

Is Base64 suitable for passwords?

No. Base64 is an encoding, not encryption, and it gives no protection, because anyone can decode it instantly. Passwords should be hashed with a secure, slow algorithm such as bcrypt or Argon2 and never stored in a reversible form.

Where is Base64 used in JWT?

A JSON Web Token has three parts, and the header and payload are Base64URL encoded. The signature is then added so the receiver can check the token was not changed. The encoding makes the data easy to carry in a URL or header, but it does not hide it.

Should I store files as Base64 in databases?

Usually not for large files. Base64 makes the data about a third bigger and adds work to encode and decode it. Binary storage or object storage is normally more efficient, with the database holding only a reference to the file.

Can decoding fail?

Yes. Decoding fails if the input has invalid characters, the wrong padding, or mixes standard and URL-safe Base64. Check for stray spaces or line breaks, and make sure you copied the whole string. The tool shows a clear message when it cannot decode.

Why does decoding show a binary data message?

The Base64 is valid but represents a file, such as an image or a PDF, rather than readable text. The tool tells you so instead of showing garbled characters. To use the file, decode it in a program that can save the result as a file.

Free, no sign-up. Reviewed 15 October 2026 by the Gopafy team. See all free tools.