OptiDrop

Base64 Encoder & Decoder Online — Encode Text & Files Free

Encode text to Base64, decode Base64 to text, and convert files to Base64 — all in your browser. No upload, no sign-up, 100% private.

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Drop a file here or click to browse

File is processed locally — never uploaded

100% Local — your file never leaves this device
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Free Online Base64 Encoder & Decoder

OptiDrop's Base64 tool lets you encode text to Base64 and decode Base64 back to text instantly. You can also convert any file to its Base64 representation using the File to Base64 feature. The entire process runs in your browser using the FileReader API — no files are uploaded to any server.

Text to Base64 and Back

Paste any text in the input field and click Encode to convert it to Base64. To reverse the process, paste a Base64 string and click Decode. The tool handles UTF-8 text correctly, so emojis and non-Latin characters are supported.

File to Base64 Conversion

Drop or select any file to convert it to Base64. This is useful for embedding files in data URIs, HTML, CSS, or JSON. The file is read locally using the FileReader API and is never uploaded anywhere. Output includes a character count so you can gauge the size of the encoded string.

100% Private & Secure

All encoding and decoding happens in your browser. No data is transmitted to any server. This makes it safe for sensitive text and files. Copy the output to clipboard with a single click.

Frequently Asked Questions

Base64 is a binary-to-text encoding scheme that represents binary data using 64 ASCII characters (A-Z, a-z, 0-9, +, and /). It is commonly used to embed binary data like images in HTML, CSS, or JSON, and to safely transmit data over text-based protocols like email and HTTP.
Use the File to Base64 section of this tool. Click the file upload area or drag and drop a file. The tool reads the file using the FileReader API entirely in your browser (no upload to any server) and displays the Base64 encoded string. You can then copy it to your clipboard.
Base64 is used when you need to embed binary data in text-only formats. Common use cases include: embedding images in HTML or CSS using data URIs, attaching files in emails (MIME), including binary data in JSON or XML, and transmitting data over APIs that only accept text.
Paste your Base64 encoded string into the input area and click the Decode button. The tool will decode the Base64 string back to its original text. Note that Base64 encoded files (like images) will produce binary data that may not display as readable text.

Last updated: June 2026