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Base64 Encoder / Decoder
Encode text to Base64 or decode Base64 to readable text in one click.
Use tool ↓Base64 Encoder / Decoder
Encode text to Base64 or decode Base64 to plain text in one click. Free Base64 encoder decoder — runs locally in your browser, no data sent to servers. This tool is designed for fast, browser-first execution so you can finish routine tasks without switching apps. Everything runs locally in your browser — your data stays on your device unless the tool explicitly calls an API.
How to Use
- Open the Base64 Encoder / Decoder tool on it3.site
- Enter or paste your input in the fields above
- Click the primary action button to process your data
- Copy or download the result for your project
- Bookmark this page for quick access later
Key Features
- Free Base64 Encoder / Decoder u2014 no signup required
- Runs entirely in your browser for privacy
- Mobile-friendly responsive interface
- Part of it3u2019s Developer tool suite
- Fast results with no file uploads to our servers (unless noted)
- Works offline after the page loads
Frequently Asked Questions
When should I use Base64 for text?
Base64 turns binary or UTF-8 bytes into an ASCII-safe string so JSON, URLs, or email headers can carry data without raw control characters. It is not encryptionu2014anyone can decode itu2014so treat Base64 as transport encoding, not secrecy. Use it for small payloads; large blobs inflate size by roughly 33%.
Why does decoding fail on pasted strings?
Whitespace, missing padding `=`, or non-Base64 characters (quotes from Word, smart punctuation) break decoders. Our tool strips common newlines, but corrupted copy from PDFs may still fail until you re-copy from a plain-text source.
Unicode vs bytes u2014 what happens?
We follow typical browser TextEncoder/TextDecoder paths: UTF-8 in, UTF-8 out for text mode. If you need legacy code pages (Windows-1252), convert upstream first; Base64 itself is ignorant of human scripts beyond the byte stream.
Is anything uploaded?
No server round-trip: encoding runs in your tab. Still avoid pasting live JWTs or keys during screen sharesu2014even u201clocal-onlyu201d tools leak through shoulder surfing.
How does this relate to data URLs?
A data URL prefix `data:text/plain;base64,` wraps the same alphabet. This tool isolates the payload so you can paste into configs that expect raw Base64 without the MIME wrapper.
Performance on huge pastes?
Megabyte-scale strings can hang the editor on low-end devices. For giant binaries, use CLI `base64` or stream through a desktop utility instead of the browser main thread.
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