Image to Base64 Encoder Free
Convert any image to a Base64-encoded data URI string online for free. Supports PNG, JPG, GIF, WebP, SVG, ICO, and more. Copy the data URI to embed images directly in HTML, CSS, or JavaScript without any external file requests. No signup required.
Drop your image here
PNG · JPG · GIF · WebP · SVG · ICO · BMP
Max 10 MB · All common image formats supported
Base64 Encoded!
Data URI (HTML img src)
CSS background-image
Raw Base64 string (no prefix)
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File size
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Base64 length
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MIME type
Pro — batch encoding, Base64 to image decoder, optimise before encoding, API
API access · Priority queue · Team workspace
How It Works
Encode any image to Base64 data URI in one step
Upload Image
Drop any image file — PNG, JPG, GIF, WebP, SVG, ICO, BMP, or TIFF. The conversion runs entirely in your browser using the FileReader API — your image is never sent to any server. This means encoding is instant and completely private, regardless of image size.
Instant Encoding
The image binary data is read and encoded to Base64 using the browser's native btoa() function. The encoder produces a data URI in the format: data:[mime-type];base64,[base64-string]. The MIME type is automatically detected from the file extension and content (PNG, JPEG, GIF, WebP, SVG+XML, etc.).
Copy & Use
Three ready-to-use outputs are generated: a data URI for use as an <img src> attribute, a CSS background-image declaration, and the raw Base64 string without the data URI prefix. Click the copy button next to any output to copy it to your clipboard, then paste directly into your HTML, CSS, or JavaScript code.
Image to Base64 Features
Fast, private, browser-side Base64 encoding for any image
100% Client-Side — No Upload
Unlike other converters, image-to-Base64 encoding runs entirely in your browser. Your image file is read using the browser's FileReader API and encoded with the native btoa() Base64 encoder — nothing is sent to any server. This means encoding is instantaneous (regardless of file size), completely private, and works even without an internet connection once the page has loaded.
All Image Formats Supported
Any image file your browser can read is supported: PNG (with transparency), JPEG, GIF (animated GIFs are encoded in full), WebP, SVG (as-is, preserving vector code), ICO, BMP, TIFF (if browser supports it), and AVIF. The MIME type is automatically set to the correct value for each format (e.g. image/svg+xml for SVG, image/avif for AVIF) in the data URI prefix.
Three Ready-to-Use Formats
Three outputs are generated automatically: (1) Data URI for <img src="..."> — paste directly as the src attribute of an img tag; (2) CSS background-image declaration — background-image: url("data:...") — paste into a CSS rule; (3) Raw Base64 string without any prefix — for use in APIs, JSON payloads, email attachments (RFC 2045), or any system that handles the MIME type separately.
One-Click Copy
Each output section has a dedicated "Copy" button that copies the entire string to your clipboard in one click using the Clipboard API. For very long Base64 strings (large images can produce hundreds of kilobytes of Base64 text), the output is displayed in a scrollable code box — you don't need to manually select the text before copying.
Instant — No Server Needed
Because the encoding happens in your browser's JavaScript engine, there are no server round-trips, no queues, and no waiting. A 100 KB PNG encodes to Base64 in milliseconds. A 5 MB JPEG still encodes in under 1 second. The tool shows the encoded output immediately after you drop the file, with no progress bar or loading spinner needed.
Use Cases
Base64 image encoding is used to: embed small icons, logos, and UI graphics directly in HTML/CSS files (eliminating extra HTTP requests); embed images in JSON API responses; include images in email HTML without file attachments; store images in databases as text strings; embed images in data: URLs for canvas operations; and include images in single-file HTML exports that must be self-contained.
Free vs Pro
| Feature | Free | Pro |
|---|---|---|
| Files per session | 1 at a time | Batch (200) |
| Encoding format | Standard Base64 | + URL-safe Base64 |
| Compress before encoding | — | |
| Base64 to image decoder | — | |
| API access | — | |
| File size limit | 10 MB | No limit |
| Privacy | Browser-only | Browser-only |
Frequently Asked Questions
A data URI is a URL that contains file data directly inline, rather than pointing to an external file. The format is: data:[mediatype];base64,[data]. For an image: data:image/png;base64,iVBORw0KGgo... — the part after the comma is the image's binary content encoded in Base64 (a text-safe encoding where each 3 bytes of binary becomes 4 ASCII characters). Browsers can use data URIs anywhere a regular URL is accepted: as an img src, CSS background-image, or link href.
Use Base64 inline images for: small icons and UI elements (under 5 KB) where eliminating the HTTP request saves more than the Base64 overhead costs; single-file HTML documents that must be completely self-contained; email HTML where external image URLs may be blocked; and favicon data URIs in HTML. Avoid Base64 for large images — Base64 encoding increases file size by ~33%, and inline images can't be cached separately by the browser, meaning every page load re-parses the Base64 string.
No — this converter runs entirely in your browser. When you drop an image, it is read by the browser's FileReader API and encoded using JavaScript's atob()/btoa() functions locally on your device. Nothing is sent to any server — the network tab in your browser's developer tools will show zero upload requests when encoding an image. This makes it completely private and suitable for sensitive images like internal documentation, medical records, or proprietary design assets.
Base64 encoding increases file size by exactly 33.3%. This is because Base64 encodes 3 bytes of binary data as 4 ASCII characters (each character being 1 byte = 8 bits, while the original 3 bytes = 24 bits are encoded as 4 × 6-bit Base64 characters). A 100 KB PNG becomes approximately 133 KB of Base64 text. Add the "data:image/png;base64," prefix (26 bytes) and any padding characters, and the total overhead is around 37% vs the raw binary file.
Yes — our Pro tier includes a Base64 to image decoder. In the browser, you can also paste a data URI directly into the browser address bar to view the decoded image. In code: in JavaScript, atob(base64String) decodes Base64 back to binary; in Python, base64.b64decode(base64_string) returns the binary bytes. You can then write those bytes to a file with the appropriate extension to recover the original image.
Yes — encoding is 100% client-side. Your image never leaves your browser. No servers involved, no uploads, no logs. Completely private.