File to Base64
🔒 In your browserConvert any file to Base64 or a data URI — in your browser.
🔒 The file is read locally with the FileReader API — it never leaves your device.
🔒 Files stay on your device: conversion happens entirely in your browser using the FileReader API — your file is never uploaded to any server, unlike many other online converters.
About the File to Base64
Sometimes you need a file as text — to inline it in JSON, a config file or as a data URI. This free file-to-Base64 converter turns any file (PDF, image, font, anything) into a Base64 string or a ready-to-use data URI, entirely in your browser.
Your file is read locally with the FileReader API and is never uploaded to a server — unlike many online converters.
How to convert a file to Base64
- Choose any file from your device.
- Copy the Base64 string, or the full data URI with the correct MIME type prefix.
- Paste it into JSON, CSS, HTML or your code.
What a data URI is for
A data URI embeds a file's contents directly in a string like data:application/pdf;base64,… so it can be used inline — in JSON, in CSS, or in code — without a separate file on disk. This tool reads any file in your browser and gives you both the raw Base64 and the ready-to-paste data URI. The file is read locally with the FileReader API and never uploaded.
Frequently asked questions
How do I convert a file to Base64?
Select the file and the tool reads it in your browser and outputs its Base64 encoding, plus a data URI you can paste directly into code or markup.
Is my file uploaded to a server?
No. The file is read locally in your browser with the FileReader API and never leaves your device.
What's a data URI?
A data URI embeds the file's contents directly in a string like data:application/pdf;base64,... so it can be used inline without a separate file.
Is my file uploaded to convert it?
No. The file is read locally in your browser with the FileReader API and never leaves your device — unlike many online converters that upload it to a server.
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🔗 Embed this tool on your website — free
Copy this and paste it into your page's HTML. The tool runs in the visitor's browser, just like here. Change height to fit, or add the optional auto-resize snippet below. Add ?theme=dark to the URL for dark mode.
<iframe src="https://toolhq.dev/embed/file-to-base64/" title="File to Base64 — ToolsHub" width="100%" height="520" style="border:1px solid #e5e7eb;border-radius:12px;max-width:680px" loading="lazy"></iframe>Optional: auto-resize the iframe height
Add this once on the same page so the iframe grows to fit the tool:
<script>
addEventListener("message", function (e) {
if (e.data && e.data.type === "toolshub:resize") {
document.querySelectorAll('iframe[src*="/embed/"]').forEach(function (f) {
if (f.contentWindow === e.source) f.style.height = e.data.height + "px";
});
}
});
</script>