What is Base64 encoding?

Base64 is a binary-to-text encoding scheme that represents binary data using 64 printable ASCII characters. It is commonly used to embed images in HTML/CSS (data URIs), encode binary data in JSON APIs, and in authentication tokens.

What is URL-safe Base64?

Standard Base64 uses + and / characters which have special meaning in URLs. URL-safe Base64 (Base64url) replaces these with - and _, making the output safe to use in URLs and filenames.

Can I encode entire files?

Yes. Switch to "File" mode to encode any file (images, PDFs, documents) to a Base64 string. This is commonly used for embedding small images in CSS as data URIs.

How do I decode a JWT token?

JWT tokens are Base64url encoded. Paste the middle section (payload) of your JWT between the two dots, select Decode, and choose URL-safe mode to read the payload.

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Base64 Encoder & Decoder

Encode and decode Base64 online instantly. Supports text and file encoding. URL-safe Base64 option. Free, fast, and private — no uploads.

Plain Text Input

About This Tool

Encode text or files to Base64 and decode Base64 strings back to plain text instantly. Supports standard Base64 and URL-safe Base64 (Base64url). Commonly used for embedding images in CSS/HTML, encoding binary data in APIs, and working with JWT tokens.