🔢 Encoding

Base64 Encoder / Decoder Online

Encode text or files to Base64, decode Base64 strings, or convert images to data URIs — entirely in your browser. No upload needed.

Advertisement

How to Use Base64 Encoder / Decoder

Select the tab for your task: Encode (text to Base64), Decode (Base64 to text), or File (convert any file to a data URI). Paste your input or upload your file — the result appears instantly.

Why Use This Tool

  • Encode tab: paste text → get Base64 output
  • Decode tab: paste Base64 string → get original text
  • File tab: upload any file → get data URI with preview
  • Copy the result or use for HTML/CSS embedding

What You Get

Text encode to Base64
Base64 decode to text
File to data URI conversion
Image preview for data URIs
Overhead percentage display
Zero server upload
Base64 Encoder / Decoder
Encode → Base64
Decode ← Base64
File → Data URI
Advertisement

Common Use Cases

Encode API credentials for HTTP Basic Auth

Base64-encode your API key and secret (username:password) for use in Authorization headers — the standard format for HTTP Basic Authentication.

Convert images to data URIs for CSS/HTML

Embed small icons and images directly in HTML or CSS as Base64 data URIs to eliminate extra HTTP requests and improve load time.

Debug JWT tokens

Decode the header and payload sections of JSON Web Tokens to inspect claims, expiry times, and token structure without needing a backend.

Encode binary data for JSON APIs

Convert images, PDFs, or binary files to Base64 strings for inclusion in JSON request bodies when uploading to APIs that don't support multipart form data.

Toolzoid Base64 vs Other Encoders

✓ Three modes in one tool
Encode text, decode Base64, and convert files to data URIs — most tools only do one of these.
✓ File upload with image preview
Upload any image and instantly see the data URI with a live preview — not just the raw Base64 string.
✓ No file size limits
Server-based encoders often limit file size. Toolzoid processes files in your browser with no arbitrary limits.
✓ Zero data transmission
Your files and text never reach any server. Essential for encoding sensitive credentials or proprietary files.

How do I encode a string to Base64 online?

Paste your text into the Encode tab on Toolzoid's Base64 tool and click Encode. The Base64 output appears instantly and can be copied with one click.

How do I decode a JWT token?

JWT tokens have three Base64URL-encoded sections separated by dots. Paste the middle section (the payload) into Toolzoid's Decode tab to see the claims.

What is a Base64 data URI?

A data URI embeds file content directly in HTML or CSS: src='data:image/png;base64,[base64string]'. Use Toolzoid's File tab to convert any image to a data URI instantly.

FAQ

What is Base64?+
An encoding scheme converting binary data to ASCII using 64 characters. Used for embedding images in HTML/CSS, JWT tokens, and API payloads.
Does Base64 compress data?+
No — it expands data by ~33%. It's encoding, not compression. For compression use gzip or Brotli.
Is Base64 encryption?+
No. Base64 is easily reversible and provides zero security. Never use it to "hide" sensitive data — use real encryption (AES, RSA) for that.

Why Use Toolzoid?

Toolzoid provides fast, privacy-first online tools that run entirely in your browser. No uploads, no tracking, no login required. Our Base64 encoder and decoder handles all three common workflows — text encoding, string decoding, and file-to-data-URI conversion — in one tool, with zero file uploads and no server processing of any kind.