Image to Base64 Converter — Encode & Decode Online
Turn any image into a Base64 data URL you can paste into code — or decode Base64 back into a downloadable image. Works in both directions, entirely offline.
Drag & drop your images here
or click to browse — several files welcome, pasting works too
Guide & tips for this tool
Why developers encode images as Base64
Base64 is a way of writing binary data — like an image — using only 64 printable ASCII characters. An encoded image becomes a long text string that can live anywhere text lives: inside a CSS file as a background, inside an HTML <img> tag as a src, inside a JSON API payload, or inline in an email template. The classic use case is eliminating a separate HTTP request for tiny assets such as icons, logos and placeholders. It is also the standard way to embed images in Markdown documents that must stay self-contained, and to shuttle pictures through systems that only accept text.
Encoding and decoding in one place
Drop an image on the zone above and the tool instantly produces a complete data URL — the data:image/png;base64, prefix included — ready to paste. A one-click copy button puts the whole string on your clipboard, and the stats panel shows the exact character count and the size overhead, which for Base64 is always about 33%: every three bytes become four characters. Working the other way? Switch to “Base64 → Image”, paste a raw Base64 string or a full data URL, and the tool decodes it, shows a preview with the real dimensions, and offers a download with the correct file extension.
When Base64 helps — and when it hurts
Inline images shine for assets under roughly 2–3 KB: a favicon, a spinner, a signature logo. Below that threshold, saving an HTTP round trip outweighs the encoding overhead, especially on HTTP/1 connections. Above it, the math flips. A 500 KB photo becomes a 680 KB text blob that cannot be cached separately, blocks rendering while the browser parses it, and is painful to diff in version control. Large images should stay files — compress them instead, and reference them by URL. The overhead readout in this tool makes the trade-off visible before you commit.
Private by construction
Encoding runs through the browser's FileReader, decoding through an <img> element — both local APIs. Your images and Base64 strings never leave the page, so the tool is safe for proprietary design assets, internal screenshots and anything covered by an NDA. No account, no logs, no size caps beyond what your device's memory can handle.
Frequently Asked Questions
What is a data URL?
A data URL embeds file contents directly in a URL, like data:image/png;base64,iVBOR.... Browsers treat it exactly like a normal image source, so it works in img tags, CSS and canvas.
How much bigger does Base64 make my image?
About 33% — every 3 bytes of binary become 4 text characters. The tool shows the exact overhead for each file you encode.
Should I Base64-encode large photos?
Usually no. Inline images cannot be cached separately and inflate your HTML or CSS. Keep assets above a few kilobytes as regular files and compress them instead.
Can I decode a Base64 string without the data: prefix?
Yes. Paste raw Base64 and the tool assumes a PNG; paste a full data URL and it uses the declared type automatically.
Is there a size limit?
No hard limit — everything happens in your browser's memory. Extremely large images produce multi-megabyte strings that some editors handle slowly.
Ratings & comments
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