Base64 Image Encoder — Core Format
FREE BASE64 IMAGE ENCODER
Online Base64 Image Encoder
Convert images to Base64 URI strings instantly. Embed small icons, logos, and UI graphics directly into HTML, CSS, or JSON without external HTTP requests.
Select an image to encode
Drag and drop a PNG, JPG, WebP, SVG, or GIF file here, or choose from device.
Supported up to 20 MB.
Browser-safe chunked string encoding.
Processed 100% locally in your browser. No files are uploaded to any server.
Ready. Select an image file to encode into Base64.
How to encode images into Base64
- Select your image: Drag and drop any image file (PNG, JPG, SVG, WebP, GIF) into the encoder.
- Choose your snippet format: Select Data URI to use in HTML/CSS src attributes, Raw Base64 for pure encoded characters, or ready-to-paste HTML <img> and CSS templates.
- Copy or Download: Click “Copy to Clipboard” to paste directly into your code, or download the full string as a plain text file.
What is Base64 encoding?
Base64 is a binary-to-text encoding scheme that converts 8-bit binary data into a sequence of 64 ASCII characters (A–Z, a–z, 0–9, +, and /). In web development, Base64 strings are prefixed with data:image/[format];base64, to create Data URIs, allowing image data to be embedded directly into HTML and CSS files.
Size comparison: Binary vs Base64
Because Base64 represents every 3 bytes of binary data using 4 ASCII characters, it introduces an inherent ~33% byte overhead. Here is how binary sizes translate to Base64:
| Original Binary Size | Base64 Encoded Size | Recommended Use |
|---|---|---|
| 1 KB (Tiny Icon / SVG) | 1.33 KB | Highly recommended (eliminates 1 HTTP round-trip). |
| 10 KB (Logo / Button) | 13.3 KB | Good for critical above-the-fold assets. |
| 100 KB (Header Banner) | 133.3 KB | Not recommended (bloats HTML/CSS bundle size). |
| 1 MB+ (Photo / Wallpaper) | 1.33 MB+ | Avoid Base64 (use external WebP/JPG with lazy loading). |
Frequently Asked Questions
Does Base64 encoding decrease image quality?
No. Base64 is a completely lossless text representation of the exact binary bytes of your file. When rendered by a browser, every single pixel is 100% identical to the source image.
Can Base64 images be cached by browsers?
Data URIs cannot be cached independently from the document they are embedded in. If embedded in a CSS stylesheet, they are cached along with the stylesheet; if embedded in HTML, they re-download every time the HTML document is requested.
Is there a file size limit for encoding?
Our tool uses browser-safe chunked string conversion, easily handling files up to 20 MB. However, for web production, images larger than 50 KB are generally better served as separate HTTP resources.