Base64 Encoder / Decoder & Image to Base64 Converter 2026 — Free Online Tool
Encode & decode text, images & files.
Encode text or images to Base64, or decode Base64 strings back to plain text/images. Features standard Base64, URL-safe Base64, and image Data URI generators with 100% private client-side processing.
Complete Guide to Base64 Encoding & Data URIs
What is Base64 Encoding?
Base64 is a group of binary-to-text encoding schemes that represent binary data in an ASCII string format. It takes 24 bits of data (3 bytes) and splits them into four 6-bit numbers, mapping each to a character in a 64-character index table.
Base64 is commonly used when there is a need to encode binary data (like images, PDF files, or encrypted tokens) that needs to be stored and transferred over media designed to handle text, such as Web APIs, JSON payloads, and HTML documents.
Standard Base64 vs. URL-Safe Base64
Standard Base64 (RFC 4648) uses + and / characters with = padding. In URL query strings or JWT headers, + and / have special URL meanings.
- Standard Base64: Uses
+and/. Ideal for email attachments and raw data storage. - URL-Safe Base64: Replaces
+with-(hyphen) and/with_(underscore), stripping padding=signs for safe HTTP URL routing.
100% Secure & Private Browser Execution
Converting sensitive API keys, JWT tokens, or proprietary graphic files on third-party servers poses serious security risks. PakTools runs all Base64 conversions 100% locally inside your browser's client-side memory using native JavaScript FileReader and TextEncoder APIs. No files or text strings are ever uploaded across the network.
How to Use This Tool
- Choose your operating mode: Text (Encode/Decode) or Image/File to Base64.
- For Text: Type or paste your string in the input box and select Encode or Decode.
- Toggle URL-Safe Mode if you are using the Base64 string in query parameters or JWT tokens.
- For Images: Drag and drop any PNG, JPG, WebP, or SVG file to generate a Data URI.
- Copy the generated output, HTML <img> tag, or CSS background-image snippet with one click.
Formula & Specifications
Base64 Encoding Math & Logic: - Maps 3 bytes (24 bits) into 4 printable ASCII characters (4 × 6 bits) - Characters used: A-Z (0-25), a-z (26-51), 0-9 (52-61), + (62), / (63) - URL-Safe Variant: replaces '+' with '-' and '/' with '_' - Size Inflation: Base64 data is ~33% larger than raw binary source bytes
About Base64 Encoder / Decoder & Image to Base64 Converter
Encode and decode Base64 strings and convert images into Data URIs instantly. Our private client-side converter supports UTF-8 multi-byte characters, URL-safe Base64 mode (RFC 4648), and instant HTML/CSS code snippet generators — 100% processed in your browser.
Frequently Asked Questions
What is Base64 encoding and why is it used?
Base64 encoding is a binary-to-text translation scheme that converts binary data (such as images, files, or non-ASCII characters) into a string of 64 printable ASCII characters (A-Z, a-z, 0-9, +, /). It is widely used in email attachments (MIME), embedding images directly inside HTML/CSS, and passing data securely in Web APIs.
What is the difference between Standard Base64 and URL-Safe Base64?
Standard Base64 uses '+' and '/' characters with '=' padding. However, '+' and '/' have special meanings in HTTP URLs. URL-Safe Base64 replaces '+' with hyphen ('-') and '/' with underscore ('_'), making the encoded string safe to use in query parameters, JWT tokens, and filenames.
How do I embed an Image as Base64 in HTML or CSS?
After converting your image to Base64, use the generated Data URI format. In HTML: <img src="data:image/png;base64,YOUR_BASE64_STRING" />. In CSS: background-image: url('data:image/png;base64,YOUR_BASE64_STRING'). This eliminates additional HTTP network requests.
Is it safe to encode or decode sensitive tokens on this site?
Yes! PakTools processes all Base64 conversions completely inside your browser using native JavaScript APIs. Your plain text strings, JWT tokens, images, and files are never uploaded to any server or logged anywhere.
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Expert Note
This tool uses the latest international formulas and rates. Results are for estimation purposes. For legal or financial decisions, consult a qualified professional. Built and maintained by the PakDigitalz team.
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