What this Base64 tool does
It converts UTF-8 text into Base64, reverses valid Base64 into plain text, and converts a local file into raw Base64 or a data URL. Supported image data URLs can be previewed without an upload.
How to use it
- Enter text and choose Encode text, or paste Base64 and choose Decode Base64.
- Use the file picker for files up to 5 MB.
- Copy the raw Base64 or complete data URL, or download the output as text.
- Reset removes the current text, output and selected file from the interface.
Practical example
The UTF-8 text “Hello, ToolNovaX 👋” can be represented as Base64 and decoded back to the same text.
SGVsbG8sIFRvb2xOb3ZhWCDwn5GLTechnical explanation
Base64 maps every three input bytes to four printable characters. This implementation uses TextEncoder and TextDecoder around byte-safe Base64 conversion so non-ASCII text is not corrupted.
Common mistakes
- Treating Base64 as encryption
- Removing required padding from some inputs
- Trying to render decoded HTML instead of treating it as plain text
- Confusing a raw Base64 payload with a complete data URL
Methodology and limitations
Files are read into browser memory and capped at 5 MB. Preview MIME types are restricted to PNG, JPEG, GIF and WebP. The tool does not inspect file safety, compress data or execute decoded content.