encoding

URL Encoder / Decoder

Encode and decode URLs, URI components, form values, and query strings locally in your browser.

URI component mode selected.

Use URI component for query values and path segments; use Full URL when you want to keep : / ? & intact.

Encoded output

Enter a value to see the result.

URL Encoding Course

Understand percent-encoding, query strings, and the difference between encodeURI and encodeURIComponent.

Course home

About this tool

DevCove URL Encoder / Decoder helps developers safely prepare URLs, query parameters, redirect targets, and form values. It supports encodeURIComponent, encodeURI, application/x-www-form-urlencoded plus-sign handling, query string parsing and building, and batch line-by-line conversion. Everything runs locally in your browser.

How to use this tool

Use this tool when you need to safely place text inside a URL, decode copied URLs, or inspect query parameters.

  1. Choose Encode or Decode for one value, or Query string when you want to inspect parameters.
  2. Select URI component for query values and path segments; select Full URL / URI when encoding an entire URL while preserving separators.
  3. Use Form value when working with application/x-www-form-urlencoded data where spaces are represented as +.
  4. Paste your input and review the live output. Invalid percent escapes are shown as errors.
  5. Use Swap to reverse an encode/decode result, Copy to reuse the output, or Copy share link to preserve the current input.
  6. Open Query string mode to parse a full URL or ?key=value string into rows, or build a query string from key/value rows.
  7. Use Batch mode to encode or decode many lines with per-row error reporting.

Features

Designed for everyday API debugging, redirect URLs, OAuth callbacks, form payloads, and query string work:

  • encodeURIComponent-style URI component encoding for query values, path segments, and redirect parameters.
  • encodeURI-style full URL encoding that preserves URL separators such as :, /, ?, &, and =.
  • Form value mode with + for spaces, matching application/x-www-form-urlencoded behavior.
  • Strict decoding with clear errors for malformed percent escapes instead of silent corruption.
  • Query string parser that accepts full URLs, ?query fragments, repeated keys, empty values, and + spaces.
  • Query string builder from tab-separated or key=value rows.
  • Batch line-by-line encode/decode for migration scripts, logs, and copied parameter lists.
  • Toolbar actions for example, clear, swap, copy, and share links.
  • 100% client-side processing—URLs, tokens, and query values are not uploaded.
  • Linked URL Encoding course with lessons on percent encoding, encodeURI vs encodeURIComponent, query strings, and plus signs.

FAQ

Should I use encodeURI or encodeURIComponent?

Use encodeURIComponent for individual query values, path segments, and redirect_uri values. Use encodeURI only for a full URL when you want to keep separators such as : / ? & = readable.

Why does a space sometimes become + instead of %20?

In application/x-www-form-urlencoded form data, spaces are commonly represented as +. General URI percent encoding uses %20. This tool has a separate Form value mode so the behavior is explicit.

Can this parse a full URL with query parameters?

Yes. Query string mode accepts either a full URL or a raw ?key=value string, extracts the query portion, decodes keys and values, and preserves repeated parameters as separate rows.

What happens with invalid percent encoding?

The decoder reports malformed input when it sees incomplete or invalid percent-encoded bytes. That makes broken copied URLs easier to spot before you put them into code or documentation.

Is my URL uploaded to DevCove?

No. Encoding, decoding, parsing, and query building run in your browser. DevCove does not upload or store your input.