About Base64 Encoder
Base64 Encoder is a free browser-based tool for converting text or files to Base64 and back. Paste some text, drop in a file, hit Encode or Decode — done. Everything runs entirely in your browser, so your data never leaves your device.
Base64 is a way of representing binary data (like image bytes, encryption keys, or non-ASCII text) using only 64 printable ASCII characters. It's used everywhere: email attachments, data URIs in CSS/HTML, JWT payloads, embedded images, API tokens, PGP-armored keys, and more.
Our encoder is UTF-8 safe (correctly handles emoji and non-Latin scripts), supports URL-safe encoding for JWT/URL contexts, and handles files up to 10 MB entirely client-side.
100% client-side: No file is ever uploaded. All encoding and decoding happens in your browser using btoa, atob, and TextEncoder/TextDecoder. Your data never touches our servers.
How to use Base64 Encoder
Get the encoded (or decoded) result in three simple steps:
Pick a mode
Choose Text mode to encode/decode strings, or File mode to convert files into raw Base64 or Data URIs.
Paste or drop
Paste text into the input, or drag a file onto the drop zone. Toggle URL-safe / line wrap options if needed.
Encode or Decode
Hit the button. Copy the result to your clipboard or download it as .txt.
Key Features
UTF-8 safe encoding
Raw btoa in JavaScript breaks on any non-ASCII character (emoji, accents, CJK). Ours wraps encoding with TextEncoder so you can encode "Hello, 世界! 👋" without errors.
URL-safe Base64 variant
One-click toggle swaps +/= for -_. Perfect for JWT payloads, URL query params, base64url-encoded API tokens, and PGP armor.
File to Base64 (any file type)
Drop a file (up to 10 MB) and get either raw Base64 or a full Data URI (data:image/png;base64,…) ready to paste into <img src>, CSS background-image, or a Markdown image tag.
MIME-standard line wrap
Optional 76-column wrap matches the MIME/RFC 2045 standard for email attachments and PEM-formatted keys. Choose 64/80 cols too, or no wrap at all.
Bidirectional with Swap
Encode → Decode round-trip works both ways. The Swap button moves output back to input so you can chain conversions.
Copy + Download
Copy button puts the result on your clipboard with a toast confirmation. Download button saves as a proper .txt file — filename derived from your input file when in file mode.
Keyboard shortcut
Ctrl+Enter (or Cmd+Enter) triggers Encode in text mode — the fastest possible round-trip.
Common Use Cases
- Encode an image or icon as a Data URI to embed directly in HTML or CSS
- Decode a JWT payload to inspect its claims (use URL-safe mode)
- Encode a small binary file for pasting into a JSON API request body
- Decode Base64 chunks copied from email raw source (MIME attachments)
- Convert an image into a shareable copy-pasteable string for chat or docs
- Prepare a PGP-armored key by hand, one section at a time
- Embed a small SVG or font in a CSS
@font-faceorbackground-image - Roundtrip-test your app's Base64 encoding to isolate encoding bugs
Security & Privacy
We take your data seriously. Here's how we protect the text and files you convert:
- 100% client-side processing: encoding and decoding runs in your browser using built-in JavaScript APIs. No file, no text, no result is ever uploaded to our servers.
- Works offline: once the page loads, you can turn off your internet and everything keeps working. Nothing needs the network.
- No tracking of content: we don't see, log, or store what you encode or decode. There's nothing for us to see.
- File size cap: 10 MB per file — a safety limit to keep the browser responsive, not for privacy (files never leave your machine).
- No accounts required: use it fully anonymously — no signup, no cookies for the tool itself.