Encode text to Base64 or decode Base64 back to plain text. Instant, free, private.
All encoding and decoding happens entirely in your browser. Nothing is sent to any server.
Base64 is a way to encode binary data as ASCII text. It's commonly used to encode images, files, and data for transmission over text-based systems like email or APIs.
No. Base64 is encoding, not encryption. It is easily reversible and provides no security. Never use it to protect sensitive data.
Common uses include encoding images in CSS/HTML, storing binary data in JSON, and transmitting data in URLs or email attachments.
Convert between plain text and Base64 in both directions, with file support — entirely in your browser.
Base64 represents binary data using 64 printable ASCII characters (A-Z, a-z, 0-9, plus + and /). It lets you transport bytes through systems that only accept text, like email or URL parameters.
No. Base64 is encoding, not encryption. There is no key and the result is trivially reversible. Never use Base64 to hide secrets — assume anything Base64-encoded is publicly readable.
That's exactly what it's designed for. Image files, ZIPs, executables — all can be Base64-encoded into a text string and decoded back to the original bytes.
Three bytes of input become four Base64 characters, so output is roughly 33% larger than input. Padding with = at the end keeps the length divisible by four.
Whenever binary data needs to travel through a text-only channel — JSON payloads, HTML attributes, CSS, email bodies, basic-auth headers, and similar. Don't use it for large payloads where you have a better option (multipart uploads, dedicated binary protocols).
Base64 encoding is one of those operations every developer hits weekly — decoding an API token, generating a data URI, building a Basic Auth header — and yet most online tools for it bury the conversion under ads, send your input to a server, or quietly truncate large inputs. The ConvertDox Base64 Encoder/Decoder does the job cleanly: paste in, click, copy out. The encode/decode happens with the browser's native btoa()/atob() and TextEncoder APIs, which means your input never travels over the network. That's important because Base64 strings often contain credentials, tokens, or PII — exactly the data you don't want a third party logging. The tool handles text in both directions and also supports small file uploads for cases where you want a data URI for a logo or favicon. Both URL-safe and standard Base64 variants are recognized on decode, so you can paste tokens copied from JWT headers, OAuth flows, and webhook payloads without worrying about character substitutions. For larger workflows, the same approach scales to the Image to Base64 tool which handles full image files; for JSON payloads with Base64 fields, our JSON Formatter pairs nicely. Bookmark this page once and Base64 stops being friction.
Base64 is a way of representing binary data — like images or files — using only plain text characters. A Base64 encoder converts text or data into this text-safe format, and a decoder converts it back. Base64 is everywhere in web development: embedding images directly in HTML or CSS, encoding data in URLs, transmitting binary data through text-only channels like email, and storing credentials in certain authentication schemes.
The reason Base64 exists is that some systems can only handle text reliably. Binary data (images, files) can get corrupted when passed through text-based systems, so encoding it as Base64 makes it safe to transmit. The trade-off is size — Base64 data is about 33% larger than the original. The ConvertDox Base64 tool encodes and decodes in your browser, so sensitive data never leaves your device. It handles both plain text and the data-URI format used for embedding.
Encode a small image as Base64 to embed it directly in a stylesheet or HTML, avoiding a separate file request.
Decode the readable parts of tokens or encoded strings to inspect their contents during debugging.
Create data-URI strings for icons, fonts, or images that load inline without external files.
Understand how binary data is encoded for transmission through text-based email protocols.
Encode or decode data that's passed as Base64 in API requests and responses.
See how username:password credentials are Base64-encoded in HTTP Basic Auth headers.
Yes, completely free with no signup and no usage limits.
No. Base64 is encoding, not encryption. It's trivially reversible and provides no security — never use it to protect passwords or sensitive data.
No. Encoding and decoding happen entirely in your browser. Your data is never sent to or stored on any server.
Base64 represents data using a limited character set, which makes the output about 33% larger than the original input. This is normal and expected.
This tool focuses on text. To convert an image to Base64, use our Image to Base64 tool, which handles image files directly.
Decoding fails when the input isn't valid Base64 — often due to extra spaces, line breaks, or characters that aren't part of the Base64 set. Clean the input and try again.