Encoding & Decoding Tools
Base64 Encoder / Decoder
Convert UTF-8 text to standard Base64 or decode standard Base64 back to text. Check Unicode, padding, and invalid bytes locally in your browser.
✓ Every tool runs in your browser. We do not upload your input or output.
Keyboard shortcuts
Ctrl/⌘ + Enter: process
Ctrl/⌘ + Shift + F: full screen
Esc: exit full screen
Ctrl/⌘ + F in editor: search
How to use
- Paste plain text or Base64 text, upload a file, or load the sample greeting.
- Choose Encode or Decode from the Operation control.
- Review the output; correct invalid characters, padding, or non-UTF-8 bytes if decoding fails.
- Copy or download the complete result after checking it.
Examples
Encode a greeting
The UTF-8 bytes are represented with standard Base64 characters and padding.
Hello, world!
SGVsbG8sIHdvcmxkIQ==
Decode text
Decode mode turns Base64 bytes back into readable Unicode text.
Q2HDp2xh
Çağla
Move text through a Base64 field
Base64 is useful when a format expects text characters but you need to represent bytes. A test fixture, API response, or configuration value may contain Base64 that you want to inspect. This tool encodes text as UTF-8 bytes before producing standard Base64, and it decodes standard Base64 bytes back into UTF-8 text. Unicode letters and emoji survive a round trip when the encoded data is valid.
Choose Encode for readable text and Decode for an existing Base64 value. Decode mode permits spaces and line breaks around the encoded characters, which helps with wrapped data copied from a document. Invalid alphabet characters, broken padding, or bytes that are not valid UTF-8 produce an error. The tool does not attempt to display binary content as if it were text.
Understand what the output means
Base64 is an encoding, not a security boundary. It makes bytes representable with a limited alphabet but does not hide their meaning. Avoid pasting secrets into any tool unless your workflow allows it; this site’s processing remains local, but the copied result is still readable by anyone who receives it. Standard Base64 uses +, /, and = padding. URL-safe Base64 substitutes other characters and is outside this tool’s current mode.
The encoder processes large text in chunks to avoid call-stack limits, and all work happens in a browser worker. The page keeps a fixed workspace height as input grows. Copy and Download use the full result rather than the shortened preview shown for very large output.
Frequently asked questions
Is Base64 encryption?
No. Anyone with the encoded text can decode it. Do not use it to protect secrets.
Can it decode arbitrary binary files?
Decode mode expects UTF-8 text. Base64 representing non-text bytes may fail rather than showing corrupted characters.
Are line breaks allowed in encoded input?
Yes. Whitespace is ignored in Decode mode so wrapped Base64 text can be pasted.
Does it support URL-safe Base64?
No. It uses the standard alphabet with + and /, plus optional = padding.
Can it handle large text?
Yes. Work runs in a Web Worker; inputs over 1 MB wait for an explicit Process action.