100% local processing — your files and data never leave this browser. No uploads, no server storage.
Free · Browser-only · No upload
Convert plain text to Base64 or decode a Base64 string back to readable UTF-8. Built for developers who need a fast base64 encode text online workflow when debugging APIs, JWT segments, or config files — without sending data to a server.
Base64 is a way to represent binary data using only printable ASCII characters. It takes every 3 bytes of input and expresses them as 4 characters from a set of 64 symbols (A–Z, a–z, 0–9, plus + and /). Padding with = appears when the input length is not a multiple of three bytes.
btoa() or atob().Browser btoa() only accepts Latin-1. We first convert your string to UTF-8 bytes with TextEncoder, then encode those bytes. That is why you can decode Base64 to text online and get back the exact emoji or accented characters you started with.
Conversions run entirely in your browser. Nothing is uploaded, logged, or stored on our servers — suitable when you need a secure Base64 decoder online for internal debugging, not production secret management.
Common questions
Practical answers about encoding, decoding, and privacy — no account required.
That usually means the original data was not UTF-8 text, or the Base64 string was truncated. If you encoded binary (like an image), decode it with a file-oriented tool instead. For plain text, make sure URL-safe mode matches how the string was created.
Processing happens entirely in your browser tab. We do not upload, log, or store your input. Still, avoid pasting production secrets on shared computers — clear the fields when you are done.
Standard Base64 uses + and / characters, which can break in URLs. URL-safe variants swap those for - and _ and often remove padding (=). JWT payloads and query strings commonly use the URL-safe form.
Yes. This tool encodes Unicode via UTF-8 before applying Base64, so characters outside ASCII (emoji, accents, CJK) round-trip correctly. Older tools that only call btoa() on raw strings often fail on those characters.
Image tools read file bytes and produce Data URIs for <img> tags or CSS. This page is for developers working with plain text — tokens, JSON fields, config snippets, and debug output from APIs.
Choose Encode or Decode, paste your content, then click Run Now (or press the mode button again). We keep it manual so you can edit input before converting large payloads.