Encode & decode URLs

URLs can only contain certain characters. Spaces, ampersands, question marks, and non-English letters must be "percent-encoded" to travel safely in a link or query string. Get it wrong and links break or parameters get lost. The web's addressing scheme was defined with a deliberately small set of permitted characters — letters, digits, and a handful of punctuation marks — because URLs have to pass through many systems that each interpret certain characters specially. A space, for instance, has no place in a raw URL, and a literal ampersand inside a parameter value would be misread as the separator between two parameters. Percent-encoding solves this by replacing any problematic character with a percent sign followed by its two-digit hexadecimal code, so a space becomes %20 and an ampersand becomes %26. A reliable encoder takes the guesswork out of which characters need this treatment, which matters because the rules about which characters are safe in which part of a URL are genuinely intricate and easy to get subtly wrong by hand.

This tool percent-encodes text for safe use in URLs and decodes encoded URLs back to readable form, instantly and locally in your browser. Everything happens on your own machine with JavaScript, so the links and parameters you paste — which can include tracking data, search queries, signed tokens, or internal endpoints — never get uploaded to a server or recorded in someone else's logs. That privacy is genuinely useful when you are working with staging URLs, authenticated links, or campaign parameters that you would rather not expose to a third-party site. Because there is no round trip to a server, the conversion is also instant: you paste, you read the result, and you copy it, with no upload delay even on long or complex URLs. You can keep working with the page open and offline once it has loaded.

Understanding the difference between encoding a whole URL and encoding a single component is the key to using percent-encoding correctly. Reserved characters such as the colon, slash, question mark, hash, and ampersand have structural meaning in a URL: they separate the scheme from the host, mark the start of the query string, delimit parameters, and so on. When you are encoding a value that goes inside a URL — a single parameter value, a search term, or a path segment — you must encode those reserved characters so they are treated as data rather than structure. This tool uses component-style encoding, which escapes reserved characters, making it the right choice for the most common task: preparing a value to drop safely into a query string. Encoding an entire assembled URL with the same aggressive rules would break it, which is why knowing what you are encoding matters.

Query parameters are where URL encoding earns its keep day to day, because they so often carry free-form, user-supplied, or campaign data. A search box that lets people type "coffee & cream" produces a value with a space and an ampersand, both of which would corrupt the URL if inserted raw — the space is illegal and the ampersand would split the value into two bogus parameters. Encoding turns that into a single, safe value that the receiving server can decode back to exactly what the user typed. The same applies to anything you append to a link: a redirect target that is itself a URL, a filter containing commas or equals signs, or a localized string with accented letters. Percent-encoding each value before assembling the query string is what keeps these parameters intact from the browser, through any intermediaries, to the server that finally reads them.

Marketing and analytics depend on correctly encoded URLs more than most people realize, and small mistakes here quietly cost data. UTM parameters and other tracking tags are appended to links so that analytics platforms can attribute traffic to the right campaign, source, and medium. If a campaign name contains a space, an ampersand, or a non-Latin character and is not encoded, the tracking value can be truncated, split, or dropped, and the resulting reports will misattribute or lose visits. Encoding each tag value before building the link guarantees that the analytics platform receives exactly the labels you intended. On the decoding side, being able to read an encoded URL back into plain text lets marketers and analysts audit existing links, confirm that parameters are populated correctly, and spot a malformed tag before it pollutes a campaign's data. Because tracking errors are silent — the link still works, it just records the wrong thing — they can go unnoticed for an entire campaign, so a quick encode-and-decode check before launch is a cheap insurance policy against weeks of misleading numbers.

A URL encoder is equally valuable for debugging, integration work, and security inspection. When a redirect misbehaves, a webhook fails, or an API rejects a request, the culprit is frequently an improperly encoded parameter, and decoding the offending URL is the fastest way to see what is actually being sent. APIs that take query parameters require values to be escaped, and a single unencoded special character can produce a confusing error far from its real cause. Being able to encode a value to test a request, or decode a captured URL to read its true contents, removes a whole class of guesswork. It also helps when reviewing links for safety, since decoding reveals whether an obfuscated URL hides a redirect or a payload that the encoded form was concealing from a quick glance.

One of the most common and frustrating bugs in URL handling is double-encoding, and understanding it saves hours of confusion. Double-encoding happens when a value that is already percent-encoded gets encoded a second time, so the percent sign of an existing escape sequence is itself escaped — a space that became %20 turns into %2520. This often occurs when a URL passes through several layers that each helpfully encode it, or when a developer encodes a value that was already safe. The symptom is a link that displays literal %25 sequences or that fails to resolve to the expected resource. A decoder makes the problem obvious: decode the URL once and if you still see encoded sequences, it was double-encoded, and decoding again or re-encoding the clean original value once will fix it. Knowing to look for this pattern turns a baffling broken link into a quick diagnosis, and it is exactly the kind of issue that a fast encode-and-decode tool resolves in moments rather than after a long, fruitless hunt through the codebase.