URL Encoder, Decoder & URL Parser

Percent-encode or decode web addresses, URI components, and query parameters. Inspect URL components, paths, and query string key-value pairs with strict RFC 3986 and UTF-8 support. 100% client-side, private, and fast.

100% Client-Side Safe
• Your data is processed locally in your browser and never uploaded.

Input URL / String

URL Output

URL Settings

Mode / StatusEncode
Output Size-
Speed-
ENGINE ARCHITECTURE & SPECIFICATION

URL Encoding, Decoding & Parsing Pipeline

A high-performance, client-side percent-encoding and URL deconstruction engine compliant with RFC 3986, RFC 1738, and WHATWG URL specifications.

🛡️

Zero-Knowledge Browser Sandboxing

100% Client-Side • 0 Telemetry

The FreeJSONtoCSV URL Encoder & Decoder executes percent-encoding, token decoding, and URL deconstruction directly inside an isolated, in-memory WebWorker sandbox. Zero URLs, authentication tokens, API query parameters, or personal data leave your device.

Sub-Millisecond

Asynchronous UTF-8 percent-encoding in WebWorker.

RFC 3986 Strict

OAuth 1.0/2.0 and AWS SigV4 percent-encoding.

Deep URL Parser

Extracts scheme, host, path, and query parameter maps.

Full UTF-8 Emoji

Safe multi-byte Unicode sequence encoding and decoding.

Processing Lifecycle

URL Transformation & Parsing Execution Flow

4-Stage Pipeline
01Ingest

Input Stream Ingest

Ingests raw URL, query string, or payload buffer into WebWorker thread.

02Tokenize

UTF-8 Byte Tokenizer

Converts Unicode code points and emoji to UTF-8 byte representation.

03Transform

Percent Escape / Decode

Applies RFC 3986 percent escapes, form plus replacement, or parser extraction.

04Export

Output & Clipboard

Renders encoded text or JSON structure ready for instant copy or download.

Common ASCII Characters & Percent-Encoded Equivalents

CharacterMeaning / FunctionStandard (%XX)RFC 3986 StrictForm (+)
SpaceWhitespace separator%20%20+
/Path segment separator%2F%2F%2F
?Query string prefix%3F%3F%3F
&Query parameter delimiter%26%26%26
=Query key-value separator%3D%3D%3D
#Fragment / Anchor identifier%23%23%23
!Sub-delimiter (OAuth strict)! (Unencoded in JS)%21%21
FAQ

URL Encoding & Decoding Frequently Asked Questions

Everything you need to know about percent-encoding, RFC 3986 standards, query strings, and privacy.

URL Encoder / DecoderWhat is the difference between encodeURI() and encodeURIComponent()?

encodeURI() is intended for complete URLs. It preserves structural protocol and delimiter characters like : / ? # [ ] @ ! $ & ' ( ) * + , ; = so the URL structure remains intact. encodeURIComponent() is intended for individual query parameter values and path segments. It encodes all delimiter characters (including & = ? /) so that special characters within values do not break the overall URL structure.

URL Encoder / DecoderWhat is RFC 3986 strict percent-encoding and why is it required for OAuth and AWS APIs?

Standard JavaScript encodeURIComponent() does not encode the characters ! ' ( ) *. However, modern authentication protocols like OAuth 1.0/2.0, Amazon AWS Signature Version 4 (SigV4), and REST API gateways strictly require all non-unreserved characters to be percent-encoded per RFC 3986. Our URL Encoder provides a Strict RFC 3986 option that safely converts these characters into %21, %27, %28, %29, %2A.

URL Encoder / DecoderWhy are spaces sometimes encoded as + and other times as %20?

In standard RFC 3986 percent-encoding (used in URL path segments and general URI components), spaces are encoded as %20. In HTML form submissions (MIME type application/x-www-form-urlencoded) and legacy query strings, spaces are historically encoded as +. Our tool lets you toggle between standard %20 and form + encoding with a single click.