Encode and Decode Base64 Online
This free Base64 encoder and decoder converts text to Base64 and decodes Base64 strings back to readable text. Paste your input, choose Encode or Decode, and copy the result. It handles full Unicode (UTF-8) text correctly, so accented characters and emoji survive the round trip. Everything runs in your browser, so your data stays private.
How to Use the Base64 Tool
- Paste your text or Base64 string into the input box.
- Choose Encode to Base64 or Decode from Base64.
- Press Convert, then copy the output.
What Base64 Is
Base64 is a way of representing binary or text data using only 64 safe ASCII characters (A–Z, a–z, 0–9, plus + and /). It was designed so that data could pass safely through systems that only handle text, such as email and URLs, without being corrupted. Encoding turns your input into that safe character set; decoding reverses it. Base64 is not encryption — it is easily reversible — so it protects against transmission errors, not against prying eyes.
Where Base64 Is Used
Base64 appears throughout the web. Images and fonts are sometimes embedded directly in HTML or CSS as Base64 data URIs to save a request. Email attachments are Base64-encoded so binary files survive text-only mail transport. JSON Web Tokens (JWTs), API keys, and HTTP Basic Auth headers use Base64. Developers constantly need to decode a Base64 string to see what is inside — for example, reading the payload of a JWT — or encode a value to embed it somewhere text-only.
Base64 Is Not Encryption
A common misconception is that Base64 hides or secures data. It does not. Anyone can decode a Base64 string in seconds, exactly as this tool does. It is an encoding, not a cipher, so never use it to protect passwords or secrets. Its real purpose is to make arbitrary data safe to store and transmit as plain text. If you need actual security, use proper encryption or hashing instead; use Base64 only for safe transport and embedding.
Private and Instant
This tool encodes and decodes entirely in your browser, so nothing you paste is sent to a server. That makes it safe for tokens and other sensitive strings, and it works instantly with no signup or limit. It also handles UTF-8 properly, so non-English text and symbols encode and decode without corruption.
Frequently Asked Questions
How do I decode a Base64 string?
Paste it above, choose Decode from Base64, and press Convert to see the original text.
Is Base64 encryption?
No — Base64 is reversible encoding, not encryption. Anyone can decode it, so never use it to secure secrets.
Is the Base64 tool free and private?
Yes — it is free, needs no signup, and runs entirely in your browser.
Reading JWTs and Data URIs
Two of the most common reasons developers decode Base64 are JSON Web Tokens and data URIs. A JWT is made of three Base64-encoded parts separated by dots; decoding the middle part reveals the token’s payload — the claims about the user or session — which is invaluable when debugging authentication. Just remember a JWT is signed, not encrypted, so its contents are readable by anyone, which is precisely why you should never put secrets in one. Data URIs embed images, fonts, or other files directly in HTML or CSS as Base64 text, and decoding lets you inspect or extract the embedded content.
Encoding is just as routine. When you need to embed a small image in a stylesheet to save an HTTP request, you Base64-encode it into a data URI. APIs that accept binary data over JSON often expect it Base64-encoded, since JSON itself is text. HTTP Basic Authentication encodes the username and password as Base64. In all these cases the goal is the same: represent data safely as plain text so it survives systems that only handle text. This tool handles the encoding and decoding instantly and in your browser, so even sensitive tokens never leave your device.