Do I need the data URI prefix?

No. A full data:image/png;base64,... URI works, and so does a bare Base64 payload — in that case the image type is detected from the decoded bytes.

How does it know the image type without a prefix?

It reads the first few decoded bytes (the file magic numbers): 0x89 0x50 means PNG, 0xFF 0xD8 means JPEG, 0x47 0x49 means GIF, an RIFF/WEBP header means WebP, and 0x42 0x4D means BMP.

Which image formats are supported?

PNG, JPEG, GIF, WebP, BMP, SVG and ICO are recognised. From a data URI the exact MIME type is used; from raw bytes the type is sniffed and defaults to PNG if unknown.

What if my Base64 has line breaks or spaces?

Whitespace and newlines are stripped automatically before decoding, so Base64 copied from emails, certificates or code wraps decodes cleanly.

Why is my decoded image broken or blank?

Usually the Base64 is truncated or contains characters from outside the image data. Make sure you copied the entire payload, including any data: prefix, with nothing cut off.

Is my image uploaded anywhere?

No. Decoding uses the browser's built-in atob and Blob APIs entirely on your device — the data is never sent to a server or stored.

What is the Base64 to Image?

Free Base64 to image decoder that turns a raw Base64 string or full data URI back into a viewable, downloadable image, detecting the type automatically. Runs entirely in your browser — nothing is uploaded. It runs free in your browser on Gera Tools, with nothing uploaded.

Base64 to Image — Gera Tools

Name: Base64 to Image
Creator: Gera Tools
License: https://creativecommons.org/licenses/by/4.0/

Decode Base64 back into an image

Paste a Base64 string — either a bare payload or a full data: URI — and get the image back, ready to view and download. This is the reverse of embedding an image as Base64 in CSS, HTML or JSON, and it is handy for inspecting data URIs pulled from a stylesheet, API response or saved page.

How it works

If the input starts with a data:image/...;base64, prefix, the tool reads the exact MIME type from it. For a bare payload it decodes the bytes and sniffs the type from the file’s magic numbers — for example a PNG starts with 89 50, a JPEG with FF D8, and a BMP with 42 4D. The decoded bytes are wrapped in a Blob of the right type, rendered as a preview, and offered for download with the matching extension.

Example

Pasting data:image/png;base64,iVBORw0KGgo... shows the PNG preview and offers a .png download. Pasting the same payload without the prefix still works — the leading bytes 89 50 4E 47 identify it as PNG automatically.

Detected bytes	Image type	Extension
`89 50`	PNG	.png
`FF D8`	JPEG	.jpg
`47 49`	GIF	.gif
`42 4D`	BMP	.bmp

Everything happens in your browser with the built-in atob and Blob APIs — nothing is uploaded.

When you need to decode a base64 image

The most common scenario is inspecting or extracting an image that arrived embedded in a data context rather than as a standalone file:

Stylesheets and HTML: A CSS background or an <img> tag may carry a data:image/...;base64,... URI directly. View-source or DevTools reveals the payload; paste it here to see and save the image.
API responses: Many image APIs return thumbnails or previews as base64 strings inside a JSON payload, particularly when the caller must remain completely serverless or the image is short-lived.
Email attachments in raw MIME: Inline images in HTML email are often embedded as Content-Transfer-Encoding: base64 blocks. Extract the block and decode it to verify the attachment.
Debug logging: Developers sometimes log base64-encoded images to trace pipelines for screenshots, OCR inputs, or computer-vision API calls. Decoding restores the visual for inspection.

Understanding the magic-number sniffing

If you paste a bare base64 payload without a data: prefix, the tool identifies the image type from the first decoded bytes — the file’s magic number:

First bytes (hex)	Format	Extension
`89 50 4E 47`	PNG	.png
`FF D8 FF`	JPEG	.jpg
`47 49 46 38`	GIF	.gif
`52 49 46 46 ... 57 45 42 50`	WebP	.webp
`42 4D`	BMP	.bmp
`3C 73 76 67` (or variant)	SVG	.svg

Magic number sniffing works because every major format reserves specific bytes at byte offset zero — a “signature” designed precisely for format detection. The MIME type in a data URI is more reliable when available, so the tool uses it first and falls back to byte-sniffing only for bare payloads.

Troubleshooting a broken decode

If the preview shows a broken or blank image, the most common causes are: the payload was truncated during copy (base64 strings can be long and break at line-wraps), the string includes URL percent-encoding that needs to be decoded first (%2B instead of +), or the data is not an image at all — it may be a different binary format that happens to be base64-encoded. The tool shows the byte count after decoding to help diagnose truncation.