Base64 Converter

Encode and decode Base64 online

Base64 is a binary-to-text encoding that represents any data using 64 safe ASCII characters, so it can travel through channels built for plain text — email bodies, JSON payloads, HTML data URIs, and HTTP headers. This free Base64 converter encodes text to Base64 and decodes Base64 back to readable text in one place, with a live output box and a one-click Copy Output button.

How to use the Base64 encoder and decoder

1. Paste your text or an existing Base64 string into the Input box.
2. Click Encode to Base64 to convert plain text into a Base64 string.
3. Or click Decode from Base64 to turn a Base64 string back into readable text.
4. Use Copy Output to grab the result. If the input is not valid Base64, the tool shows an error instead of a broken result.

Worked example: encode and decode a login string

Suppose an API expects HTTP Basic authentication with the username admin and the password s3cret. The header value is the Base64 of admin:s3cret.

1. Paste admin:s3cret into the Input box and click Encode to Base64.
2. The output is YWRtaW46czNjcmV0, so the header reads Authorization: Basic YWRtaW46czNjcmV0.
3. To go back, paste YWRtaW46czNjcmV0 and click Decode from Base64. You get admin:s3cret again, which shows why Base64 is encoding, not encryption.

Non-English text works too: नमस्ते encodes to 4KSo4KSu4KS44KWN4KSk4KWH and decodes back unchanged.

Common uses for a Base64 converter

• Reading or building data: URIs for inline images, fonts, and other embedded assets.
• Inspecting Base64 values found in config files, API responses, and environment variables.
• Encoding small blobs so they survive systems that only accept text.
• Decoding Basic Authentication headers and other Base64-wrapped credentials while debugging.

Everything runs in your browser

All encoding and decoding happens locally in your browser using native JavaScript — your text is never uploaded, logged, or stored on our servers. That makes it safe for sensitive strings you would rather not paste into a random online service. Note that Base64 is encoding, not encryption: anyone can decode it, so it is not a way to protect secrets.

Working with the parts of a token or URL-encoded data? A JSON Web Token is just Base64url segments — inspect one with our JWT decoder — and for percent-encoded query strings use the URL encoder and decoder.

Need a custom tool or internal developer utility built for your team? Get in touch with SR Infobiz.