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Base64 Encoder / Decoder

Encode and decode Base64 text and files, with Data URL generator.

UTILITY

✓ Free ✓ No sign-up ✓ Instant results

URL-safe Base64

Input

Output

Click to upload or drag & drop

ℹ️ About this tool ▼

Free Online Base64 Encoder & Decoder

QuickTools Base64 Encoder lets you encode and decode Base64 strings and files directly in your browser. Switch between Text mode for encoding or decoding plain text and File mode for converting any file into a Base64 Data URL ready to embed in HTML, CSS or JSON. The tool auto-detects whether your input is already Base64-encoded and switches direction automatically. Enable URL-safe mode to replace +/ with -_ for tokens and URLs. Live stats show input and output byte sizes plus the size overhead percentage. Everything runs 100% client-side — your data never leaves your machine. Perfect for developers embedding images, generating API payloads, debugging encoded strings or creating inline assets for emails and single-page apps.

How to Encode or Decode Base64

Choose Text or File mode. For text, type or paste your content and the tool encodes it automatically. Toggle to Decode if you have a Base64 string. For files, drag and drop or click to upload — the tool generates a full Data URL and a raw Base64 string you can copy separately.

Why Use This Tool

Auto-detection of encode/decode direction, URL-safe mode, file-to-Data-URL conversion, and live size stats — all in one page. 100% client-side, no upload limits, no signup.

FAQ

What is Base64 encoding?

Base64 is a binary-to-text encoding that represents binary data as an ASCII string using 64 characters (A-Z, a-z, 0-9, +, /). It is commonly used to embed images in HTML, transmit data in URLs or encode email attachments.

Is there a file size limit?

There is no hard limit since everything runs in your browser. However, very large files (over 50 MB) may slow your browser. For most use cases like images and documents, the tool works instantly.

What is URL-safe Base64?

URL-safe Base64 replaces + with - and / with _ and strips trailing = padding. This makes the output safe for use in URLs, filenames and JWT tokens without additional encoding.

What is a Data URL?

A Data URL embeds the file content directly in a URL using the format data:[mime];base64,[data]. It lets you include small images or files inline in HTML or CSS without a separate HTTP request.