Developer topics · Updated 2026-10-04
URL Encoding Explained
URLs can only carry a limited character set safely in some components. Percent-encoding represents other bytes as %HH sequences so separators like & and = keep their structural meaning.
The rule of thumb
Encode the values you insert into a query string or path segment—not the entire URL with its scheme and slashes already in place.
Spaces: %20 vs +
encodeURIComponent always emits %20. Older application/x-www-form-urlencoded bodies use + for space. Most servers accept both in query strings; do not assume every decoder does.
SmartKitio behavior
- URL Encoder uses encodeURIComponent semantics.
- URL Decoder converts + to space first, then applies decodeURIComponent.
- Invalid % sequences produce an error instead of silent corruption.
- All processing stays in the browser.
Try these SmartKitio tools
Use a tool when you want a result; keep this guide open when you want the method.
Browse family: Developer Tools
Related articles
Broader reading that connects to this guide—when the topic deserves more than a how-to.
- Encoding vs Encryption: What's the Difference?
Encoding, encryption, hashing, and compression solve different problems. Confusing them—especially Base64 with secrecy—creates real security failures.
- How a Web Browser Actually Works
From typing a URL to painting pixels—what the browser is doing under the calm address bar.
- What Happens When You Enter a URL?
A step-by-step path from keypress to first paint, including DNS, TLS, redirects, and caching.
- What Is an API and How Does It Work?
APIs are contracts between programs. HTTP JSON APIs are the visible face—methods, headers, bodies, status codes, auth, and versioning explained.
Related guides
- Base64 Encoding Explained
How Base64 maps bytes to ASCII, why length grows, and how SmartKitio encodes UTF-8 text.
- HTTP Status Codes Explained
What the major 1xx–5xx classes mean, with the codes developers meet most often.
- JSON Formatting and Validation: Complete Guide
What strict JSON allows, how pretty-printing works, and how SmartKitio’s formatter behaves.
- JSON vs JSON5: What's the Difference?
Why JSON5 feels nicer to type, and why production APIs still standardize on strict JSON.