Base64 Encoder and Decoder Online — Encode Text, Base64URL, Files
Convert Base64 text
Result updates as you type
URL-safe alphabet (- and _ instead of + and /)
Encode text to Base64 or decode Base64 back to readable text in real time, with a Base64URL toggle that swaps the standard + and / characters for the URL-safe - and _ so JWTs, OAuth tokens, and webhook signatures work without further escaping. Live mode encodes as you type, while File mode turns any uploaded file into a Base64 string or rebuilds a binary file from a Base64 payload — ideal for embedding favicons, web fonts, and small images as data URIs that cut HTTP requests on your site. Use it to build Basic-Auth headers and API bearer tokens, package OAuth or webhook payloads, or inline tiny images and SVGs directly into HTML and CSS for faster page loads. The tool also decodes data URIs and Base64-encoded JWT segments so you can inspect headers and payloads during debugging. Everything runs 100% locally in your browser — your tokens, keys, and file contents are never uploaded to a server.
Embed assets and debug API payloads with Base64
Inline small icons, SVGs, and fonts as Base64 data URIs to cut HTTP requests and speed up Core Web Vitals, or decode incoming Base64 from API responses, OAuth tokens, and Basic Auth headers during debugging. A Base64URL toggle swaps the standard + and / for URL-safe - and _ and strips the padding, so the encoded output is safe to drop into a JWT, a query parameter, or a filename. Live mode re-encodes on every keystroke so you can watch the output update as you type.
File-to-Base64 and back, without uploading anything
Switch to file mode to convert any local file to a Base64 string, or paste a Base64 string and download the decoded binary back to disk — useful for inspecting attachments, regenerating PDFs from API responses, and pulling images out of JSON payloads. The entire encode/decode loop runs in your browser, so private documents, signed contracts, and credentials never traverse a third-party server. There is no file-size warning for typical payloads.