🔐 Base64 Encoder & Decoder — Free Online Tool

Encode text or files to Base64 and decode Base64 strings back to text. All in your browser.

📝 Text to Encode
🔓 Base64 to Decode
📁 File to Base64
📁

Drop any file here

or click to browse — converts file to Base64 data URL

🖼 Base64 Image Preview

What is the Base64 Encoder / Decoder?

The Base64 Encoder/Decoder is a free, browser-based tool for encoding text and binary files into Base64 format, and for decoding Base64 strings back to their original content. Base64 is a binary-to-text encoding scheme that represents binary data using only 64 printable ASCII characters. It is widely used in web development, APIs, email systems, and data storage to safely transmit binary data through channels that only support plain text.

Common use cases include encoding authentication credentials for HTTP Basic Auth headers, embedding images directly in HTML or CSS as data URLs (eliminating extra HTTP requests), encoding binary API request payloads in JSON, embedding font files in stylesheets, and transmitting binary attachments in MIME email formats. Developers frequently need to encode and decode Base64 strings while debugging APIs, building authentication flows, or working with data URIs.

How to Use — Step-by-Step

  1. Select the Encode tab to encode text, or Decode to decode a Base64 string.
  2. For encoding: type or paste your text and click Encode. The Base64 output appears instantly below.
  3. For decoding: paste your Base64 string and click Decode to recover the original text.
  4. Use the File to Base64 tab to convert any file (image, PDF, etc.) into its Base64 data URL representation.
  5. Use the Image Preview tab to paste a Base64 image string and preview it visually before downloading.
  6. Copy output to clipboard or download as a .txt or .b64 file with one click.

Key Features & Benefits

⚡
Live Encoding

Text is encoded to Base64 in real-time as you type, with character count ratios shown immediately.

📁
File to Base64

Convert any file type — images, PDFs, audio, video — into a Base64 data URL ready to embed in code.

🌐
URL-Safe Encoding

Optional URL-safe mode replaces + and / with - and _ for safe use in URLs and query parameters without escaping.

🖼
Image Preview

Paste a Base64 image string to preview it visually in the browser and download the recovered image file.

🔒
100% Private

All encoding and decoding happens in your browser. Sensitive credentials, API keys, and file content never leave your device.

🆓
Always Free

No account, no limits, no watermarks. Encode and decode Base64 as often as you need for free.

Frequently Asked Questions

❓ Is the Base64 tool free to use?
Yes, completely free with no usage limits, no account requirements, and no hidden fees. Encode and decode Base64 as many times as you need.
❓ Is my data secure? Does it upload my content?
Your text and files are never transmitted to any server. All encoding and decoding operations use JavaScript's built-in btoa() and atob() functions locally in your browser. Sensitive API keys, authentication tokens, and file content remain private on your device.
❓ Is Base64 a form of encryption?
No. Base64 is an encoding scheme, not encryption. It transforms binary data into a printable text representation that can be decoded by anyone without a key. It should not be used to protect sensitive data — use proper encryption like AES for security. Base64 is purely for safe data transmission in text-based systems.
❓ Why does the Base64 output string end with == or =?
Base64 groups data into 3-byte chunks and encodes each as 4 characters. If the input length is not divisible by 3, padding characters (=) are added to make it so. One = means one byte of padding was needed; == means two bytes. This is normal and expected behavior in standard Base64 encoding.
❓ What file types can I convert to Base64?
Any file type can be Base64-encoded using the File to Base64 tab — images (PNG, JPG, GIF, WebP), PDFs, audio files (MP3, WAV), fonts, JSON files, and more. The tool reads the file as a binary data URL and outputs the Base64 portion for use in code or APIs.