Free Base64 encoder and decoder — convert text and files to Base64 and back. Free online Base64 converter tool.
Encode and decode Base64 strings and files. Convert text to Base64, Base64 to text, or files to Base64. Works 100% in your browser.
Input Text
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Maximum file size: 10MB
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Base64 Output
Result will appear here
Disclaimer: This tool processes all data locally in your browser. No text or files are sent to any server. File conversion is limited to 10MB per file.
What the Base64 Encoder/Decoder Does and Why It Matters
This tool converts text and files to and from Base64, the encoding that represents binary data using a safe set of printable characters. Encoding turns arbitrary bytes into an ASCII string; decoding reverses it back to the original content.
Base64 shows up wherever binary data has to travel through text-only channels: embedding an image in CSS or HTML as a data URI, attaching files in email (MIME), storing small blobs in JSON, or passing credentials in an HTTP header. Doing the conversion in the browser means even file contents never leave your device.
How to Use Base64 Encoder/Decoder
Choose whether to encode or decode.
Type or paste text, or select a file to convert.
Run the conversion and review the output.
For decoding, paste a Base64 string to recover the original text or file.
Copy the result, or download it when the output is a file.
Clear the fields when you are finished.
Supported Inputs and Limitations
Supported input
Plain text in either direction
Local files for encoding to Base64
A Base64 string for decoding
What you get
A Base64 string when encoding
The decoded text or downloadable file when decoding
Copy-ready output for code or configuration
Known limitations
Base64 is encoding, not encryption; it offers no confidentiality and is trivially reversible.
Encoded data is roughly one third larger than the original, which matters for large files.
Decoding only succeeds on valid Base64; truncated or altered input will fail or produce garbage.
Privacy and Security
Encoding and decoding run entirely in your browser, so text and file contents are never uploaded to NovaTools. Nothing is stored after you close the tab. Remember that Base64 does not hide data — anyone can decode it — so never treat it as a way to protect secrets.
Frequently Asked Questions
Is Base64 a form of encryption?
No. It is a reversible encoding designed to make binary data text-safe. Anyone can decode it instantly, so it provides no security or confidentiality on its own.
Are my files uploaded when I encode them?
No. File reading and encoding happen locally in your browser using the File API, so the contents never leave your device.
Why is my decoded output empty or broken?
The input is probably not valid Base64 — it may be truncated, contain stray characters, or use a different variant. Re-copy the full string and ensure no characters were lost.
Base64 is a binary-to-text encoding scheme that represents binary data in an ASCII string format. It's commonly used for transmitting data over channels that only support text content, embedding images in HTML/CSS, storing binary data in JSON, and many other applications. This free online tool lets you encode text or files to Base64, or decode Base64 back to its original form.
How to Use
Select your conversion mode: Text to Base64, Base64 to Text, or File to Base64.
Enter your text or upload a file (max 10MB).
Click Convert to perform the encoding/decoding.
Use Copy to copy the result or Download to save it.
Frequently Asked Questions
What is Base64 encoding used for?
Base64 is used to encode binary data as text for transmission over text-based protocols, embedding images in HTML/CSS using data URIs, storing binary data in JSON or XML, email attachments (MIME), and URL parameters that need to handle special characters.
Is my data kept private?
Yes, completely. All encoding and decoding happens locally in your browser using JavaScript. No data is ever transmitted to any server or stored anywhere.
What's the maximum file size?
The file upload is limited to 10MB per file to ensure smooth performance in your browser. For larger files, consider using command-line tools or desktop applications.
Can I decode Base64 back to a file?
When you decode Base64 text, the result will appear in the output area. If the decoded content represents a file (like an image), you can copy the output and use it in data URIs or save it with the appropriate file extension.
Why does my Base64 look different on different systems?
Base64 encoding is standardized (RFC 4648), so the encoded output should be consistent. However, line breaks and padding characters (=) might be handled differently by various systems. This tool produces standard Base64 without line breaks.
Recommended next reading
Use these practical guides to understand when this tool is the right choice, what to check before exporting, and which workflow usually comes next.
