Base64 Decoder — Decode Base64 Strings to Text
Decode any Base64-encoded string back to readable text or download the original binary file. Supports standard and URL-safe Base64 alphabets.
When You Need to Decode Base64
Developers encounter Base64 strings in email attachments (MIME encoding), data URIs in HTML and CSS, JWT token payloads, API responses that embed binary data, and database fields that store serialized content. Decoding reveals the original content so you can inspect, debug, or extract it.
Decoding URL-Safe Base64
URL-safe Base64 replaces + with - and / with _ to avoid issues in URLs and query strings. This tool auto-detects the variant by checking for the presence of - or _ characters and decodes accordingly. You can also manually toggle between standard and URL-safe mode.
Frequently Asked Questions
Base64 strings consist only of A-Z, a-z, 0-9, +, /, and = characters. They are typically a multiple of 4 characters long and may end with one or two = padding characters. The tool validates the input and warns you if it is not valid Base64.
Yes. If the decoded data is an image (PNG, JPEG, GIF, SVG, WebP), the tool displays a preview and provides a download button so you can save the image file directly.