What this page covers
Base64 encoding represents binary data as ASCII text using 64 URL-safe characters.
Quick answer
Encode strings to Base64 or decode payloads back to plain text. Ideal for JWT segments, API testing, and debugging. Free in your browser on Case Modify—no… Use it in a browser with no account required, then review the output before publishing or shipping.
Part of Code & data tools
Base64 encode and decode: convert text and binary-safe strings
Base64 encoding represents binary data as ASCII text using 64 URL-safe characters. Developers use it for embedding small images in data URLs, passing binary blobs through JSON, or decoding tokens and headers during debugging—not for encryption or compression.
This tool encodes and decodes UTF-8 text in the browser. It is ideal for quick experiments, not for secrets management or large files.
How to use this converter
- Paste text to encode, or a Base64 string to decode.
- Switch between Encode and Decode modes.
- Copy the result; verify padding (`=`) when decoding legacy payloads.
Base64 is encoding, not encryption
Anyone can decode Base64. Do not treat encoded passwords or API keys as protected. Use proper encryption and secret stores in production. Base64 only changes representation so binary-safe transports (email, JSON strings) can carry bytes.
UTF-8 text, padding, and URL-safe variants
Text is encoded as UTF-8 bytes before Base64. Decoding assumes standard Base64 alphabet; URL-safe variants (`-` and `_`) may need normalization in strict decoders. Padding characters at the end are required for some libraries—include them when decoding fails.
Common debugging uses
Inspect JWT payload segments (middle part only—verify signatures in proper tools). Decode a Basic auth header during API troubleshooting. Encode a small SVG for a data URL prototype. For images, dedicated image-to-Base64 workflows may be more convenient.
Before and after examples
| Original | Converted | Notes |
|---|---|---|
| Hello | SGVsbG8= | Simple ASCII encode |
| SGVsbG8= | Hello | Decode |
Frequently asked questions
Is Base64 the same as encryption?
No. It is reversible encoding with no secret key.
Can I encode files?
This page targets text pasted into the box. Very large inputs may be truncated for responsiveness.
Why does decoding fail?
Check for missing padding, line breaks in the paste, or URL-safe alphabet differences.
Related guides
How to use this tool
- Paste text to encode, or a Base64 string to decode.
- Switch between Encode and Decode modes.
- Copy the result; verify padding (`=`) when decoding legacy payloads.
Related pages on Case Modify
URL Encode & Decode — Fix broken links and special characters in URLs.
UTF-8 Encoder — See UTF-8 byte sequences or recover text from encoded data.
Frequently asked questions
Is Base64 the same as encryption?
No. It is reversible encoding with no secret key.
Can I encode files?
This page targets text pasted into the box. Very large inputs may be truncated for responsiveness.
Why does decoding fail?
Check for missing padding, line breaks in the paste, or URL-safe alphabet differences.
Related guides
Examples
| Before | After | Notes |
|---|---|---|
| Hello | SGVsbG8= | Simple ASCII encode |
| SGVsbG8= | Hello | Decode |
Related Tools
Hex to Text Converter: Convert hex strings to readable text or text to hex.
URL Encode & Decode: Fix broken links and special characters in URLs.
UTF-8 Encoder/Decoder: See UTF-8 byte sequences or recover text from encoded data.
What Is Base64 Encoding?: What Is Base64 Encoding?