Free Base64 Encoder / Decoder Online
Free Base64 Encoder / Decoder Online is a free online tool by US AI. Encode & decode text. It runs completely in your browser — no signup, no download, works on mobile and desktop.
📖 How to use
- Type or paste text and press Encode to get Base64, or paste Base64 and press Decode to read it.
- Open the tool with the button above — it loads instantly.
- Your work stays on your device; nothing is uploaded anywhere.
✨ Why use this tool?
US AI's free base64 encoder / decoder online is fast, private and 100% free forever. Bookmark this page and share it with anyone who needs it.
⚡ Quick examples
Converting text to Base64 and back is instant. Here are two real examples you can try in the tool above:
| Text | Base64 |
|---|---|
Hello | SGVsbG8= |
US AI | VVMgQUk= |
❓ Frequently asked questions
What is Base64 encoding used for?
Base64 turns text or binary data into a plain ASCII string — commonly used to embed images in HTML and CSS, encode email attachments, and pass tokens in URLs and APIs.
How do I decode a Base64 string?
Paste the encoded string and press Decode — the original text appears immediately, processed entirely in your browser.
Is Base64 a form of encryption?
No. Base64 is encoding, not encryption — anyone can decode it, so never use it to hide passwords or sensitive secrets.
Why does my decoded text look like gibberish?
This usually means the string uses a different Base64 alphabet (URL-safe Base64 uses - and _ instead of + and /), is missing its = padding, or the original data was not UTF-8 text (for example an image decoded as text). Paste the exact original string and try again.
What does the = padding at the end mean?
Base64 output is always a multiple of 4 characters, so = (one or two) fills the gap when the input is not a multiple of 3 bytes. The padding is required for correct decoding — do not trim it.
Can I encode an image or file to Base64?
This tool converts text only — type or paste text to get its Base64. To encode an image or other file, use a dedicated file-to-Base64 converter, which reads the file's bytes and encodes them the same way.
What is the difference between Base64 and URL-safe Base64?
Standard Base64 uses + and /, which break URLs; URL-safe Base64 swaps them for - and _. This tool outputs standard Base64 — for URL-safe output, replace + with -, / with _ and trim trailing = characters.