Base64 Encoder & Decoder
Encode any text string or file to Base64 format, or paste a Base64 string to decode it back to plain text. Handles both standard and URL-safe Base64 variants.
How to Use the Base64 Encoder & Decoder
Choose the Encode or Decode tab depending on what you need to do. Select Standard for regular Base64 or URL-safe if the output will appear in a URL or JWT. Paste your text or Base64 string into the input panel and click the action button. The result appears instantly in the output panel on the right. Use Copy to grab it to your clipboard or Download .txt to save it as a file.
What Is Base64 Encoding?
Base64 is an encoding scheme that converts binary or text data into a set of 64 printable ASCII characters
(A–Z, a–z, 0–9, +, and /). This makes it safe to transmit data through channels that only handle text, such
as email MIME attachments, CSS data: URLs, and HTTP headers. Base64 does not encrypt data — it
simply re-represents it. The encoded output is approximately 33% larger than the original. Common uses
include embedding images directly in HTML, encoding credentials for Basic Auth headers, carrying binary
payloads in JSON, and storing binary blobs in databases that only accept text.
Standard vs URL-Safe Base64
Standard Base64 uses + and / as its 62nd and 63rd characters, and pads output with
= to a multiple of four characters. Both + and / have special meanings
in URLs — + means a space in query strings, and / is a path separator — so they
must be percent-encoded if the Base64 string appears in a URL. URL-safe Base64 solves this by replacing
+ with - and / with _, and dropping the =
padding. The result can appear directly in query strings, path segments, and JWT tokens without any
additional encoding.
Why Use a Browser-Based Base64 Tool?
API credentials, JWT tokens, and configuration values are routinely Base64-encoded. Pasting them into an
online tool that sends data to a server creates unnecessary exposure — logs, analytics, and request traces
can all capture that data. This tool processes everything locally in your browser using the built-in
btoa(), atob(), TextEncoder, and TextDecoder APIs. No
data leaves your device. There are no file size limits, no sign-up requirements, and no server ever sees
your input.