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Base64 Encoder

Encode text or files to Base64, and decode Base64 back to text. Works entirely in your browser.

Plain Text 0 chars
Base64 Output 0 chars

About Our Base64 Encoder / Decoder

Base64 is one of those technologies that quietly powers the modern internet, yet most people have never heard of it. Every time you see an image embedded directly inside a web page, receive an email attachment, or log into an API using Basic Authentication, Base64 is doing the heavy lifting behind the scenes.

Our Base64 encoder and decoder gives you a simple way to convert text or files to Base64 format, and to decode any Base64 string back to its original form. Everything runs in your browser — no signup, no uploads, no limits on how many times you can use it.

How to Use the Base64 Tool

Whether you are encoding or decoding, the workflow is straightforward:

  1. Choose your mode — Encode to convert text or a file into Base64, or Decode to convert Base64 back into readable text.
  2. For encoding, choose between Text mode (paste any text) or File mode (upload an image, PDF, or any other file using drag-and-drop or the file picker).
  3. Paste or type your input into the left panel. If "Auto-convert" is on, the output appears instantly as you type.
  4. Copy or download the result using the buttons below the panels.

Why Use Our Base64 Encoder

There are many Base64 tools online, but ours is built with a few key priorities that make it stand out:

  • 100% private. Your text and files never leave your browser. No server, no logging, no tracking. This is especially important when working with sensitive text or confidential documents.
  • Unicode-safe. Many basic Base64 tools break when you paste Hindi, Arabic, or emoji. Ours uses the modern TextEncoder API, so any Unicode character is handled correctly.
  • URL-safe mode. Standard Base64 uses + and /, which are unsafe in URLs. Our URL-safe toggle swaps them for - and _, making the output perfect for URLs, filenames, and JWT tokens.
  • File encoding. Need to embed a small image directly in HTML or CSS? Upload the file, and we will convert it to a Base64 data URL that you can paste anywhere.
  • Auto-detect decode. When decoding, our tool automatically recognises URL-safe Base64 and converts it back without errors.

How Base64 Works

Base64 works by taking groups of 3 bytes (24 bits) of binary data and representing them as 4 printable ASCII characters. The 64 characters used are A-Z, a-z, 0-9, plus + and /. If the input length isn't divisible by 3, one or two = characters are appended as padding.

The result is pure text that can be safely transmitted through channels that only handle printable characters — email, HTML, JSON, XML, URLs, and configuration files. The trade-off is a size increase of approximately 33% compared to the original binary data.

Common Uses for Base64

You will find Base64 in many places once you start looking for it:

  • Embedding small images directly in HTML, CSS, or JSON using data URLs
  • Email attachments via MIME encoding
  • HTTP Basic Authentication headers (username:password encoded)
  • JSON Web Tokens (JWT) for user authentication
  • Storing API keys or certificates in environment variables and config files
  • Encoding binary data inside XML documents
  • Representing cryptographic keys in PEM files

Frequently Asked Questions

What is Base64 encoding?

Base64 is a way of representing binary data as text using 64 printable characters (A-Z, a-z, 0-9, +, /). It is commonly used to embed images or files inside text-based formats like HTML, CSS, JSON, and email.

Is Base64 a form of encryption?

No. Base64 is an encoding scheme, not encryption. Anyone can decode a Base64 string back to the original data without any key. If you need to protect sensitive information, use proper encryption like AES.

Why does Base64 make data larger?

Base64 uses 4 characters to represent every 3 bytes of binary data, so the encoded output is about 33% larger than the original. This size increase is a trade-off for making binary data safe to transmit through text-based channels.

Is my data safe when using this tool?

Yes. All encoding and decoding happens entirely in your browser using JavaScript. Your text or files are never uploaded to any server, stored, or shared. Even if you disconnect from the internet after loading the page, the tool continues to work.

What is URL-safe Base64?

Standard Base64 uses "+" and "/" characters, which have special meanings in URLs. URL-safe Base64 replaces them with "-" and "_" respectively, making the encoded string safe to use directly in URLs, filenames, and JWT tokens.

Can Base64 handle Unicode characters like Hindi or emoji?

Yes. Our tool uses the TextEncoder API to first convert your text to UTF-8 bytes and then encodes those bytes to Base64. This ensures that Hindi, Chinese, Arabic, emojis, and any other Unicode characters are handled correctly.

Is there a size limit for files?

We recommend keeping files under 10 MB for smooth browser performance. Larger files will still work, but may cause the browser to slow down or run out of memory, since everything is processed on your device.

Where is Base64 commonly used?

Base64 appears in many everyday places: data URLs for inline images in HTML/CSS, email attachments via MIME, API authentication tokens (Basic Auth), JSON Web Tokens (JWT), and configuration files that need to store binary data as text.

Related Tools You Might Find Useful

If you found this Base64 tool helpful, you might also want to try our JSON Formatter for pretty-printing JSON data, our URL Encoder for percent-encoding URLs, or our Image Compressor for reducing image file sizes before embedding.