Image to Base64 Converter – Free Online Tool
Convert JPG, PNG, WebP, or SVG images to Base64 encoded strings. Download the data URL as a .txt file for embedding in HTML, CSS, or code.
No signup · No limits · Works on any device
What Is Base64 Image Encoding?
Base64 image encoding converts binary image data into a text string that can be embedded directly in HTML, CSS, SVG, JSON, or any other text-based format. Instead of a URL pointing to an image file (like /images/logo.png), a base64-encoded image is a long text string starting with "data:image/png;base64," followed by hundreds or thousands of characters representing the binary image data encoded as ASCII text. Base64 images are used extensively in web development and email. In HTML, base64-encoded images can be embedded directly in img tags using data URLs — eliminating an extra HTTP request for small images or icons. In CSS, base64 images can be used as background-image values. In email templates, some email clients block external image loading but will display base64-encoded inline images. SVG files can embed base64 images to create self-contained vector graphics with embedded raster content. In JavaScript and backend code, base64 encoding is used when an API requires image data as a string (rather than a file upload) — for example, many AI image APIs, browser extension messaging, and localStorage/sessionStorage (which can only store strings) use base64 for image data. Base64 encoding increases file size by approximately 33% — a 100 KB image becomes approximately 133 KB as a base64 string. This is acceptable for small images, icons, and favicons used inline. For large images meant for web delivery, base64 is not appropriate. FileQuick reads your image using the browser's FileReader API and outputs the complete data URL string as a downloadable .txt file.
Why use FileQuick?
Getting a base64 data URL for an image traditionally requires code (JavaScript's FileReader, Python's base64 module, or an online tool). FileQuick makes this a point-and-click operation — upload an image, get a .txt file with the data URL, copy the string into your HTML/CSS/code. No command line, no library imports, no coding required. Useful for frontend developers embedding small icons, email template designers, and anyone who needs to paste an image as a string.
How to Convert an Image to Base64 Online — Step by Step
- Click 'Upload Files' or drag and drop your JPG, PNG, WebP, or SVG image into the drop zone.
- FileQuick reads the image using the browser's FileReader API — your file stays on your device.
- Click 'Convert to Base64'. The image is encoded as a complete data URL string.
- A .txt file downloads containing the full base64 data URL. Copy the string and paste it wherever needed.
Frequently Asked Questions
Is the image to base64 converter free?
Yes, completely free — no account, no payment, no limits.
What is a base64 data URL?
A data URL is a URI scheme that embeds data inline. For images, it looks like: data:image/png;base64,[encoded-string]. It can be used directly as an image src or CSS background-image value.
How much larger is a base64 image than the original?
Base64 encoding increases size by approximately 33%. A 100 KB PNG becomes approximately 133 KB as a base64 string.
What image formats are supported?
JPG/JPEG, PNG, WebP, and SVG. The data URL includes the correct MIME type for each format.
Are my files uploaded to a server?
No. The FileReader API reads the file locally in your browser. Your image never leaves your device.