Is Base64 encryption?

No, Base64 is an encoding. It converts bytes into a text-safe alphabet using a fixed, public algorithm, so decoding requires no key or password, and anyone with the string can recover the original text.

Can someone decode my Base64 string without a password?

Yes, decoding Base64 requires nothing beyond the string itself, since the mapping between bytes and characters is fixed and public, not a secret. If the content needs to stay confidential, encrypt it before encoding.

What is the difference between standard and URL-safe Base64?

Standard Base64 uses + and / in its alphabet, which have special meaning in URLs; URL-safe Base64 replaces them with - and _ so the string can appear in a URL or filename without extra encoding.

Why does decoding my Base64 fail?

Decoding fails when the input contains characters outside the Base64 alphabet, or has a length that can't correspond to whole bytes even after restoring padding, which usually means the string was truncated or copied incorrectly.

Base64 Encode / Decode

Encode text to Base64 or decode Base64 back to text, with URL-safe support, all local.

Local, Runs entirely in your browser, your data never leaves your device.

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Encode or decode Base64 without sending anything to a server

Base64 shows up constantly in API tokens, JWT segments, embedded images and Basic Auth headers, and it is common to need the plain text behind one, or to produce a Base64 string from scratch. This tool encodes arbitrary UTF-8 text to Base64 and decodes Base64 back to text, with a toggle for the URL-safe alphabet used in tokens and query strings. Everything runs locally in your browser, which matters because a Base64 string frequently hides an API key, session token or other credential.

How to use the Base64 Encode / Decode

Choose Encode or Decode from the mode toggle above the input.
Paste text to encode, or a Base64 string to decode, into the left panel.
Turn on URL-safe if you're encoding for use in a URL or a token that uses - and _ instead of + and /.
Read the result on the right, and use the swap button to flip direction with the current output carried over.
Copy the result, or send it to another tool such as the JWT decoder.

Base64 is an encoding, not encryption: it maps bytes to a 64-character alphabet in a fixed, publicly known way, so anyone, not just you, can decode it back to the original bytes with no key or password required. Treat it as obfuscation for transport, never as a way to protect a secret.

Decoding accepts both the standard alphabet (+ and /) and the URL-safe alphabet (- and _), and restores missing = padding automatically, so pasting a token straight from a URL or a JWT segment works without edits.

Frequently asked questions

Is Base64 encryption?: No, Base64 is an encoding. It converts bytes into a text-safe alphabet using a fixed, public algorithm, so decoding requires no key or password, and anyone with the string can recover the original text.
Can someone decode my Base64 string without a password?: Yes, decoding Base64 requires nothing beyond the string itself, since the mapping between bytes and characters is fixed and public, not a secret. If the content needs to stay confidential, encrypt it before encoding.
What is the difference between standard and URL-safe Base64?: Standard Base64 uses + and / in its alphabet, which have special meaning in URLs; URL-safe Base64 replaces them with - and _ so the string can appear in a URL or filename without extra encoding.
Why does decoding my Base64 fail?: Decoding fails when the input contains characters outside the Base64 alphabet, or has a length that can't correspond to whole bytes even after restoring padding, which usually means the string was truncated or copied incorrectly.