File to Data URL Creator

Convert any file to a Base64 Data URL, encode text as a data URI, or decode a Data URL back to a downloadable file. 100% client-side.

Drag & drop a file here

or browse to select — any file type

Drop a file above or enter text to generate a Data URL.

How to Use the Data URL Creator

  1. File to Data URL — drag and drop any file to instantly generate its Base64 Data URL. Images are previewed inline. The size comparison shows the original vs encoded size.
  2. Text to Data URL — enter any text (HTML, SVG, CSS, JSON) and select a MIME type. The Data URL updates live. Toggle Base64 encoding for binary-safe output.
  3. Data URL to File — paste any Data URL to decode it. Images are previewed; all file types can be downloaded back as the original file.

What Is a Data URL?

A Data URL (or data URI) is defined in RFC 2397. It embeds file content directly in a URL string using this format:

data:[<mediatype>][;base64],<data>

For example, a small red pixel PNG might look like: data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAADUlEQVR42mP8/5+hHgAHggJ/PchI6QAAAABJRU5ErkJggg==

Data URLs are supported in all modern browsers in HTML <img> tags, CSS background-image properties, <script> and <link> tags, and anywhere a URL is accepted. They bypass the browser's HTTP cache (since the data is inline) and eliminate a network round-trip, which is beneficial for very small files.

When to Use Data URLs

Data URLs work best for small, frequently reused assets where eliminating an HTTP request outweighs the 33% size overhead:

  • Small icons and favicons — embed a 1 KB icon directly in your HTML or CSS
  • Loading spinners — avoid a request for a tiny GIF or SVG animation
  • Email HTML — many email clients block external images; embedded Data URLs always display
  • CSS background images — patterns and gradients under 5 KB
  • Inline SVGs in CSS — complex vector icons that change color via CSS filter
  • Auto-generated reports — self-contained HTML files with all assets embedded

When Not to Use Data URLs

Avoid Data URLs for:

  • Large images — a 500 KB photo becomes 667 KB of text and cannot be cached separately
  • Files used on multiple pages — a separately cached asset file loads once; a Data URL re-transmits every page load
  • Resources that change frequently — cache invalidation is harder since the URL contains the content

SVG Data URLs

SVG files can be used as Data URLs without Base64 encoding. A plain text SVG can use URL encoding: data:image/svg+xml,%3Csvg...%3E. This is often smaller than the Base64 equivalent. The Text mode in this tool generates both formats. For related tools, see the Base64 Encoder/Decoder and File Checksum Verifier.

Frequently Asked Questions

A Data URL (data URI) is a URL scheme that encodes file data directly in the URL string using Base64. Format: data:MIME_TYPE;base64,BASE64_DATA. Data URLs let you embed images, fonts, CSS, and other files directly in HTML or CSS without separate HTTP requests. Supported in all modern browsers.
Base64 encoding converts binary data to text using 64 ASCII characters. Every 3 bytes of binary becomes 4 characters of Base64, resulting in a 33% size increase. A 1 MB image becomes a 1.37 MB Data URL. For small files the eliminated HTTP request usually outweighs this overhead.
Data URLs work best for small files (under 10 KB): small icons, loading spinners, email HTML images, CSS background patterns, and self-contained HTML reports. Avoid for large images or frequently reused assets that benefit from browser caching.
No. This tool uses the browser's FileReader API to read your file entirely in your browser. No data is sent to any server. You can safely use this tool with sensitive documents, private images, or proprietary files.
Switch to 'Data URL to File' mode, paste the full data URL (starting with data:), and click Decode. The tool extracts the MIME type, decodes the Base64 data, previews images inline, and provides a download button for the reconstructed file.