Base64 Encoder / Decoder

Encode and decode Base64 — text and files, URL-safe variant supported.

Converter Text & Encoding Updated Apr 19, 2026
How to Use
  1. Paste text in the top box to encode. Paste Base64 in the output to decode.
  2. Toggle URL-safe variant if needed.
  3. Drop a file to encode binary.
Text / file
Or drop a file
Base64

About Base64

Alphabet
A–Z a–z 0–9 + / (URL-safe: - _)
Overhead
≈ 4 / 3 × input bytes
Padding
= used to reach 4-char boundary
Spec
RFC 4648

About the Base64 Encoder / Decoder

Whether you are at a desk or on your phone, the Base64 Encoder / Decoder makes text, encoding and string work easy — and it is completely free. Encode and decode Base64 — text and files, URL-safe variant supported.

How it works

Type a value, then pick what you want to change it into. The answer appears straight away. It all happens on your own device, so it is fast and nothing you type is sent away. Just check that you picked the right “from” and “to” so you get the answer you wanted.

Want the deeper story? The Knowledge Base explains the ideas behind the tools in more detail.

Frequently Asked Questions

URL-safe?

Standard Base64 uses "+" and "/"; URL-safe swaps them for "-" and "_". Padding "=" can also be dropped.

Size overhead?

Base64 is 4/3 the size of the original binary — expect ~33% growth.

How do I use the Base64 Encoder / Decoder?

Just type or paste your value. The answer shows up right away — there is no button to press. Change anything and it updates by itself.

Is it free? Does it work without internet?

Yes to both. It is free with no sign-up, and once the page has loaded it keeps working even with no internet.

Where does my data go?

Nowhere — every calculation runs on your own device. Nothing you enter is uploaded, logged, or stored.

Common Use Cases

Data URIs

Embed images in CSS / HTML.

JSON payloads

Ship binary in JSON text fields.

Last updated: