Online Encoding & Decoding Tools

Free online tools for Base64, URL, HTML, and string encoding and decoding. All processing runs in your browser — nothing is uploaded to a server.

Encoding converts data from one representation to another — the output is deterministic and reversible. These tools cover the encoding operations developers reach for most often.

Base64 is ubiquitous: it embeds images in CSS data URIs, encodes binary email attachments (MIME), and passes binary data through text-only channels. URL encoding (percent-encoding) ensures query parameters with special characters are transmitted safely per RFC 3986. HTML entity encoding prevents cross-site scripting by converting characters like < into safe entities.

All encoding happens locally in your browser. No data is sent to any server.

All Encoding Tools
Base64 Encode
Encode text or binary data to Base64. Supports standard and URL-safe alphabets.
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Base64 Decode
Decode a Base64 string back to readable text or binary.
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URL Encode
Percent-encode a string for safe use in URLs and query parameters.
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URL Decode
Decode percent-encoded URL strings back to readable form.
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HTML Encode
Escape characters to HTML entities (&lt;, &amp;, etc.). Also decodes.
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JS String Escape
Escape or unescape JavaScript string literals, including Unicode sequences.
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Python String Escape
Escape a string to a valid Python string literal.
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Python String Unescape
Unescape Python escape sequences back to their original characters.
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