Developer
Base64 Encode and Decode Online
- Browser-based
- No signup
Base64 encode and decode online for API payloads, data URLs, and config files. Paste plain text to encode or paste Base64 to decode—runs locally in your browser for quick developer and support tasks.
Base64 is encoding, not encryption—anyone can decode it. Never hide secrets with Base64 alone.
UTF-8 text needs proper encoding before Base64—this tool handles typical Unicode strings in the browser.
100% Client-Side
Your data never leaves your computer.
How to use this tool
Paste input text, choose encode or decode, and copy the output. Switch direction without leaving the page.
Worked example
Example: decode `SGVsbG8gV29ybGQ=` to `Hello World` when debugging a JWT header or API response field.
When to use this
- Debugging API responses with Base64 fields.
- Building data URLs for small inline assets.
- Teaching encoding in workshops.
Common examples
- UTF-8 email header value → Base64 for debugging MIME parts.
- Small JSON claim → Base64 segment inspection before JWT assembly.
- Data URL prefix stripped → decode image bytes from `data:image/png;base64,...` payloads.
- Small SVG icon → data URL for inline HTML email test.
- UTF-8 string with emoji → Base64 for API fixture matching production encoding.
What people search for
- base64 encode decode
- base64 encoder online
- base64 decoder
- encode string base64
- base64 converter
Common mistakes
- Confusing Base64 with encryption.
- Decoding binary data as UTF-8 text and getting mojibake.
- Forgetting URL-safe Base64 variants use different alphabet.
Related long-tail tasks
- base64 image to data uri
- url safe base64 encode
- base64 decode jwt payload
How it works
Choose Encode or Decode, then paste or type text. Encoding converts UTF-8 text to standard Base64. Decoding accepts standard or URL-safe Base64 (with optional whitespace) and returns the original text. All processing runs in your browser.
Limitations
Results are based on the inputs you provide and may not cover every edge case. This tool is for general use and is not professional advice.
Privacy and file handling
Your data is processed in your browser and is not uploaded to our server.
Related Base64 Encoder & Decoder guides
These pages use the same base64 encoder & decoder with guides tailored to specific search intents.
Frequently asked questions
Is Base64 encryption?
No. It is reversible encoding for binary-safe text transport.
Are inputs logged?
Standard Utilnivo encode/decode runs locally without sending text to a server.
Padding characters?
Base64 output may end with = padding. Some APIs require or forbid padding—trim if needed.
Related tools
Related pages
- Browse all free online tools on Utilnivo
- Explore more developer tools on Utilnivo
- Base64 Encoder & Decoder — Encode and decode text with Base64.
- JWT Decoder — Decode JWT tokens to inspect header and payload claims.
- JSON Formatter — Format, minify, and validate JSON with optional key sorting.
- JSON Compare — Compare two JSON documents and list structural differences.
- XML Formatter — Format, minify, and validate XML with readable indentation.
- XML Compare — Compare two XML documents and list structural differences.
Page last reviewed: