Base64 to Image Converter

A Base64 converter is a tool that translates binary data (images, PDFs, files) into a text-based format made up of 64 printable ASCII characters (A–Z, a–z, 0–9, +, /). It also works in reverse — taking that encoded text string and reconstructing the original data. It’s essentially a universal translator between binary files and plain text.

A few common reasons: Base64 strings are used extensively in web development to embed images directly in HTML/CSS, in APIs and JSON payloads that can’t carry raw binary, in email attachments (MIME encoding), and in JWTs and cryptographic tokens. Converting back from Base64 lets you inspect, preview, or save the original file when you only have the encoded string.

Show stats — when active, displays a stats bar after every conversion showing the raw byte size, the Base64 character count, and the overhead ratio (Base64 is always ~33% larger than the original data). Useful for understanding the size cost of encoding.
Auto-strip data URI prefix — Base64 strings often come wrapped in a data:image/png;base64, style header. When this is on, the tool automatically strips that prefix before decoding so you don’t have to clean it up manually. Turn it off if you want to feed raw Base64 without any prefix detection.
Uppercase hex — only relevant in Hex mode. Toggles whether the hex output is rendered in lowercase (a3f9) or uppercase (A3F9). A matter of preference or matching whatever format a downstream system expects.
Spaced hex bytes — also only relevant in Hex mode. When active, inserts a space between each byte (a3 f9 cc) rather than running them together (a3f9cc). Makes the hex dump easier to read manually, though the raw run-together format is more common for copy-pasting into code.
In short — the first two affect all modes, while the last two are specifically for fine-tuning the Hex output format.

t depends on your browser’s memory, not a server limit — since everything runs locally. In practice, most modern browsers handle files up to around 50–100 MB without issues. Very large files (hundreds of MB) may slow down or crash the tab because the entire file is loaded into JavaScript memory. For anything production-scale and large, a server-side tool would be more appropriate.

The tool uses native browser APIs entirely — no server, no uploads, no third parties. atob() decodes the Base64 string into binary, which is then handed to whichever conversion path you chose: a data: URI rendered in an <img> tag for images, a Blob URL opened in a new tab for PDFs, a manual byte-to-hex loop for hex output, or TextDecoder for text. File encoding uses the FileReader API to read your uploaded file and produce the Base64 data URI.

Completely. It’s a single HTML file that runs entirely in your browser with no account, no backend, no telemetry, and no cost. You can save it to your desktop and use it offline indefinitely.