Base64 Encode and Decode – Online Tool with Advanced Options

Use 99tools.in’s Base64 Encoder/Decoder to quickly convert text or files with advanced settings like charset, line breaks, and URL-safe encoding. 100% free and secure.

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Need to quickly encode or decode Base64 data? You’re in the right place. The Base64 Encode/Decode Tool on 99tools.in makes it fast and easy to convert text, files, or binary data to and from Base64 — right in your browser.

Whether you’re a developer working with APIs, securing data, or just curious about how Base64 works, our tool gives you full control with smart options and zero hassle.

🔁 What is Base64 Encoding?

Base64 is a binary-to-text encoding scheme that lets you represent binary data (like images, files, or special characters) as readable text using ASCII characters. It’s commonly used in:

  • ✅ Email attachments (MIME)
  • ✅ Data URIs in HTML/CSS
  • ✅ JWT (JSON Web Tokens)
  • ✅ API headers
  • ✅ File storage or transfers

⚙️ What You Can Do With This Tool

Encode Text to Base64
Convert any string or content into a Base64-encoded format instantly.

Decode Base64 to Text
Paste your encoded string and get the original text or binary content back.

Upload & Encode Files
Easily convert file contents (text, JSON, images, etc.) to Base64.

Advanced Options

  • Choose character encoding: UTF-8, ASCII, ISO-8859-1, etc.
  • Enable URL-safe encoding (for JWTs, URLs)
  • Add or remove line breaks or newline delimiters
  • Split output into fixed-length lines (MIME-style)

✅ Fully Client-Side
Everything happens in your browser — no data is uploaded, making it 100% secure and private.

🧠 Why Use Base64?

  • 🔐 Encode sensitive data for safe transfer or storage
  • 🌐 Make binary data web-safe (e.g., for HTML and CSS)
  • 🧪 Debug and decode APIs, JWTs, or scripts
  • 🛠️ Test integrations that rely on encoded strings

👨‍💻 Who Is This Tool For?

  • Web Developers & API Engineers
  • Backend/DevOps Professionals
  • Cybersecurity & QA Testers
  • Students learning about data encoding
  • Anyone needing a quick encode/decode tool!

How to Use the Tool

  1. Step 1: Open the Tool

    Go to 99tools.in/tools/base64-encode-and-decode using your web browser. The tool is free, online, and doesn’t require any login.

  2. Step 2: Choose an Action

    Decide what you want to do:
    Encode: To convert plain text or files into Base64
    Decode: To revert Base64 back to original format
    You can toggle between the two modes using the tool’s simple interface.

  3. Step 3: Enter Your Data

    Paste the text you want to encode or decode in the main input box.
    You can also click on the “Upload File” button to load files (like JSON, images, or text files).

  4. Step 4: Set Advanced Options (Optional)

    For more control, you can:
    Select character set (e.g., UTF-8, ASCII)
    Enable URL-safe Base64 encoding
    Add or remove line breaks
    Choose output formatting like line-length splitting
    These are useful for developers or working with APIs.

  5. Step 5: Click the Convert Button

    Click the “Encode” or “Decode” button based on your selected mode.
    The converted result will appear instantly in the output box.

  6. Step 6: Copy or Download Your Output

    You can copy the result to your clipboard or click on “Download” to save it as a file.
    And you’re done! Quick, private, and efficient.

FAQ

What is Base64 encoding used for?

Base64 encoding is used to convert binary data (like images, files, or special characters) into ASCII text. It’s commonly used in web development, email encoding (MIME), APIs, and secure data transfer.

Can I decode Base64-encoded images or files?

Yes, you can. Just paste the Base64 string or upload the file, and the tool will decode it back to its original format. This is useful for restoring encoded assets or testing integrations.

Is this Base64 tool secure?

Absolutely. All encoding and decoding is done 100% client-side in your browser. Your data never leaves your device, ensuring complete privacy and security.

What advanced options are available?

You can choose character encoding (like UTF-8, ASCII), enable URL-safe Base64 (for JWTs), add/remove line breaks, and split output into fixed line lengths for MIME compatibility.

Do I need to install anything to use this tool?

No installation is needed. Our Base64 Encode/Decode tool runs directly in your browser. It’s completely free, lightweight, and accessible from any device.