How to use this tool
- Choose "Text → Base64" or "Base64 → Text" from the tabs.
- Paste your input — the result updates as you type.
- Copy the result with the copy button.
Common mistakes to avoid
- Don't paste Base64 with surrounding quotes or a data: URI prefix into the decoder — just the encoded characters themselves.
- A "not valid Base64" error almost always means the text was truncated during copy-paste — check the length matches what you copied.
Why encode Base64 in the browser instead of an online converter?
Base64 is often used to encode sensitive material — an auth token for a Basic Authentication header, a secret embedded in a config file, or an API key someone's debugging. Posting that to a third-party server to decode it defeats the point. This tool uses the browser's native TextEncoder/btoa/atob APIs, so nothing you type is ever transmitted anywhere.
Frequently asked questions
- Does this handle non-English text and emoji correctly?
- Yes — the text is encoded as UTF-8 before Base64-encoding, so accented characters, non-Latin scripts, and emoji round-trip correctly. A plain btoa() call in JavaScript breaks on these; this tool handles it properly.
- What is Base64 actually used for?
- Embedding binary-ish data in text-only contexts — e.g. inline images in CSS/HTML (data: URIs), email attachments, or auth headers like Basic Authentication.
- Why does decoding sometimes fail?
- The input has to be valid Base64 — correct alphabet (A-Z, a-z, 0-9, +, /) and correct padding (=). Stray whitespace or a truncated copy-paste is the most common cause.
- Can I encode or decode a whole file?
- Not on this page — it's built for text. For files, most modern needs (like inline images) are better served by your browser's or editor's built-in tools.
How GetByteRush compares
Most free tools for this online work the same way: you upload your file to their server, wait, then download the result — which means your file (and often your email, for a "free" account) sits on someone else's infrastructure. Here's the actual difference:
| Feature | GetByteRush | Typical online Base64 converters |
|---|---|---|
| Data ever leaves your device | No — 100% client-side | Often yes — posted to a server endpoint |
| Correct Unicode/emoji handling | Yes — proper UTF-8 encoding | Varies — plain btoa() breaks on non-Latin1 text |
| Account required | Never | Sometimes |
("Typical online tools" reflects publicly documented behavior of common free file-processing sites as of 2026 — always check a specific competitor's own privacy policy and pricing page, since these details change.)