FreeKit is a collection of free online tools for developers, SEO professionals, designers, students, content creators, and everyday users.

Are all tools completely free?

Yes. Every tool on FreeKit is free to use without subscriptions or hidden charges.

Do I need to create an account?

No. You can use all tools instantly without creating an account.

No. Most tools process data locally in your browser, and we do not permanently store your inputs.

Can I use FreeKit on mobile devices?

Yes. Every tool is fully responsive and works on smartphones, tablets, laptops, and desktop computers.

How often are new tools added?

We regularly add new tools and improve existing ones based on user feedback and industry needs.

Which browsers are supported?

FreeKit supports all modern browsers, including Chrome, Edge, Firefox, Safari, and other Chromium-based browsers.

Can I share these tools with others?

Absolutely. You are welcome to share FreeKit with friends, colleagues, students, and your team.

What is URL encoding (percent encoding)?

URL encoding, also known as percent encoding, is a mechanism to encode special characters in URLs so they can be safely transmitted over the internet. It replaces unsafe ASCII characters with a percent sign (%) followed by two hexadecimal digits. For example, a space becomes %20, a question mark becomes %3F, and an ampersand becomes %26. This ensures that URLs remain valid and unambiguous, since certain characters like ?, &, and / have special meaning in URL syntax.

What is the difference between encodeURI() and encodeURIComponent()?

encodeURI() is designed to encode a full URL and preserves characters that have special meaning in URLs, such as :, /, ?, #, &, =, and @. It only encodes characters that are truly unsafe in any part of a URL. encodeURIComponent(), on the other hand, encodes all characters except A-Z, a-z, 0-9, -, _, ., ~ — including characters like /, ?, &, and = which are needed as URL structure delimiters. Use encodeURIComponent() when encoding query parameter values or individual segments, and encodeURI() when encoding a complete URL that should remain structurally valid.

Which characters must be encoded in a URL?

RFC 3986 defines two categories of characters: reserved characters (:, /, ?, #, [, ], @, !, $, &, ', (, ), *, +, ,, ;, =) that have special meaning in URLs, and unreserved characters (A-Z, a-z, 0-9, -, _, ., ~) that are always safe. Any character outside the unreserved set should be percent-encoded when it does not serve a structural purpose. Additionally, non-ASCII characters (like é, 你, emoji) and control characters must always be encoded, typically as UTF-8 byte sequences (e.g., é becomes %C3%A9).

Why does my URL-encoded string have %20 for spaces?

The space character is not safe in URLs and must be encoded. There are actually two valid encodings for a space: %20 (percent encoding, recommended by RFC 3986) and + (application/x-www-form-urlencoded format, used in query strings from HTML forms). Our encoder uses %20 as the standard percent-encoding format. If you need the + encoding for form data, you can post-process the result by replacing %20 with +, or use URLSearchParams which follows the form-encoding rules.

How do I encode query parameters correctly?

When building query strings, each parameter name and value should be individually encoded with encodeURIComponent(). For example, to create the query ?name=John Doe&city=New York, encode the value of each parameter: encodeURIComponent('John Doe') produces 'John%20Doe', and encodeURIComponent('New York') produces 'New%20York'. Never encode the entire URL with the query string assembled, as that would also encode the ?, &, and = delimiters that structure the query. The 'Encode values only' toggle in our tool handles this automatically.

What does the 'invalid encoded input' error mean when decoding?

This error occurs when the input string contains percent-encoded sequences that are not valid. Common causes include: a % sign not followed by exactly two hexadecimal digits (e.g., %2G instead of %2F), incomplete percent sequences at the end of the string (e.g., trailing %2), or malformed UTF-8 byte sequences (e.g., %C3 alone without a continuation byte). Our tool catches these errors and displays a specific message to help you identify and fix the problematic part of the input.

What is the difference between URL encoding and HTML entity encoding?

URL encoding replaces characters with %XX hex sequences for safe transmission in URLs. HTML entity encoding replaces characters with named or numeric entities (like & for &, < for ) for safe rendering in HTML documents. They serve different purposes: URL encoding protects URL structure and transmits data in web addresses, while HTML entity encoding prevents XSS attacks and ensures characters display correctly in web pages. You should use the appropriate encoding for each context.

How are non-ASCII characters like emojis or Chinese text encoded in URLs?

Non-ASCII characters are first converted to UTF-8 bytes, and then each byte is percent-encoded individually. For example, the emoji 😊 (U+1F60A) becomes the UTF-8 bytes F0 9F 98 8A, which encodes to %F0%9F%98%8A. The Chinese character 你 becomes the UTF-8 bytes E4 BD A0, encoding to %E4%BD%A0. This is why a single non-ASCII character can become a long percent-encoded sequence. Our tool handles this conversion automatically using the built-in encodeURIComponent() function.

Should I encode the entire URL or just the parameter values?

It depends on your use case. If you have a complete URL like https://example.com/path?key=value, you should encode only the individual parameter values (the parts after =), not the entire URL. Encoding the entire URL would break the ://, ?, and & separators. If you have a fragment of text that you want to safely include in a URL, encode the entire fragment. Our tool provides a toggle to switch between encoding the full input (using encodeURI for full URLs or encodeURIComponent for text) and encoding values only.

Is URL encoding the same as encryption or hashing?

No, URL encoding is neither encryption nor hashing. It is a reversible encoding that anyone can decode instantly — there is no key, cipher, or one-way transformation involved. Its sole purpose is to make text safe for transmission in URLs by replacing unsafe characters with percent-encoded representations. It provides zero security or obfuscation. If you need to protect data in URLs, use HTTPS for transport security or proper encryption for sensitive parameter values.

URL Encoder/Decoder

Encode and decode URLs and query parameters.

BeginnerDeveloper ToolsFreev1.0.0Updated Jun 10, 2025

Auto-encode as you type

Encode full URL (encodeURI)

Text / URL Input0 chars

Encoded Output0 chars

Stats:Input: 0 charsOutput: 0 charsEncoded chars: 0

Common URL-Encoded Characters

Character	Encoded	Description
␣	%20	Space
!	%21	Exclamation mark
"	%22	Double quote
#	%23	Hash / fragment
$	%24	Dollar sign
%	%25	Percent sign
&	%26	Ampersand
'	%27	Single quote
(	%28	Left parenthesis
)	%29	Right parenthesis
+	%2B	Plus sign
,	%2C	Comma
/	%2F	Forward slash
:	%3A	Colon
;	%3B	Semicolon
=	%3D	Equals sign
?	%3F	Question mark
@	%40	At sign
<	%3C	Less than
>	%3E	Greater than

100% Private — Your Data Never Leaves Your Browser

All URL encoding and decoding is performed entirely in your browser using client-side JavaScript. No data is sent to any server, stored, or tracked.

How to Use the URL Encoder/Decoder

Choose your mode — Select Encode to convert text to percent-encoded format, or Decode to convert percent-encoded strings back to readable text. Click the mode buttons in the toolbar or use the dedicated Encode/Decode action buttons.
Select encoding type — When encoding, choose whether to encode the full URL (preserves structural characters like :// and ? using encodeURI) or encode values only (encodes everything including /, ?, and = using encodeURIComponent). Use full URL mode for complete web addresses, and values-only mode for query parameter values.
Enter your input — Type or paste your text into the input textarea on the left. For encoding, enter any text including URLs, query strings, or text with special characters. For decoding, paste a percent-encoded string.
Encode or Decode — Click the Encode or Decode button to process your input. Alternatively, enable the auto-encode toggle for real-time processing as you type. The result appears instantly in the output panel.
Copy or Swap — Click Copy Output to copy the result to your clipboard. Use the Swap button to move the output back to the input and flip the mode, useful for round-trip verification.

Features

Encode mode with two strategies: encodeURI() for full URLs and encodeURIComponent() for values
Decode mode using decodeURIComponent() to convert percent-encoded strings back to readable text
Full URL toggle to preserve structural URL delimiters (://, ?, &, =) when encoding complete web addresses
Auto-encode toggle for instant real-time processing as you type
Reference table of 20 common URL-encoded characters with hex values and descriptions
Stats bar showing input length, output length, and count of encoded/decoded characters
Swap button to quickly move output to input and flip between encode/decode modes
Clear error display for invalid percent-encoded input with specific guidance
Side-by-side layout on desktop, stacked layout on mobile for comfortable editing
100% client-side processing — your data never leaves your browser

Understanding URL Encoding

What is Percent Encoding?

Percent encoding (URL encoding) is defined in RFC 3986 as a mechanism to represent arbitrary data in URIs using only the limited set of US-ASCII characters allowed in URLs. Characters that are not in the unreserved set (A-Z, a-z, 0-9, -, _, ., ~) are replaced with a % sign followed by two hexadecimal digits representing the character's byte value. For example, a space (ASCII 32, hex 20) becomes %20.

encodeURI vs encodeURIComponent

JavaScript provides two encoding functions. encodeURI() preserves characters that have structural meaning in URLs (:, /, ?, #, &, =, +, @), making it suitable for encoding complete URLs. encodeURIComponent() encodes all characters except A-Z, a-z, 0-9, -, _, ., ~, making it ideal for encoding individual query parameter values. Using the wrong function is a common source of bugs — our toggle lets you switch between them easily.

Reserved vs Unreserved Characters

RFC 3986 defines reserved characters (:, /, ?, #, [, ], @, !, $, &, ', (, ), *, +, ,, ;, =) as having special meaning in URI syntax. Unreserved characters (A-Z, a-z, 0-9, -, _, ., ~) never need encoding and can appear literally in any URI. When a reserved character appears in a non-structural context (like a ? in a query value), it must be percent-encoded.

UTF-8 in URL Encoding

URL encoding works on bytes, not characters. Non-ASCII characters like emojis, accented letters, and CJK text are first converted to UTF-8 byte sequences, then each byte is individually percent-encoded. For example, the é character becomes the UTF-8 bytes C3 A9, encoding to %C3%A9. This means a single non-ASCII character can produce up to 9 characters in a percent-encoded URL (for 4-byte UTF-8 sequences like emojis).

Common Use Cases

API Query Parameters

Encode parameter values when constructing API URLs to ensure special characters like spaces, ampersands, and equals signs don't break the query string structure.

Web Form Data

Understand how browsers encode form submissions and decode URL-encoded form data received from application/x-www-form-urlencoded POST requests.

URL Sharing and Links

Encode URLs that contain special characters before embedding them in emails, social media posts, or other contexts where the URL might be mangled.

Debugging API Requests

Decode percent-encoded URLs from browser dev tools, server logs, or API documentation to understand the actual parameter values being sent.

Redirect URLs

Encode redirect target URLs when passing them as query parameters (e.g., ?redirect=/page?a=1&b=2 must be properly encoded to avoid parsing errors).

SEO and Canonical URLs

Ensure URLs contain only safe ASCII characters for search engine crawlers. Non-ASCII characters in slugs should be percent-encoded for proper indexing.

Data URI Parameters

Encode data within data URIs or custom URL schemes where special characters could be misinterpreted as delimiters.

Webhook and Callback URLs

Encode callback URLs that contain query parameters when passing them as values in other query strings or configuration fields.

URL Encoder/Decoder Tips

If you need to encode binary data or authentication payloads for transmission, use our Base64 Encoder — it converts arbitrary data into a 64-character ASCII representation suitable for JSON, email, and data URIs.
When embedding user-generated text into HTML templates, first URL-encode it here, then use our HTML Entity Encoder to convert special characters like <, >, and & into entity references for XSS prevention.
If your encoded URL contains JSON query parameters, decode them first with this tool, then paste the result into our JSON Formatter to beautify and validate the structure.
Enable the 'Encode full URL' toggle when you have a complete URL with colons, slashes, and question marks that should be preserved as structural delimiters. It uses encodeURI() instead of encodeURIComponent(), keeping :///?= reserved characters intact.
The Swap button moves the output to the input area and flips between encode and decode modes — perfect for round-trip testing to verify your encoded strings decode back to the original text.
Enable auto-encode for instant feedback as you type. This is especially useful when working with API query strings where you want to see the encoded result in real time as you build parameter values.
Spaces in URLs are encoded as %20 by default (the RFC 3986 standard). Note that some legacy systems use + for spaces in application/x-www-form-urlencoded data — our tool always uses the standard %20 format.
The reference table below the tool shows 20 commonly encoded characters with their hex values. Use it as a quick lookup when you need to manually verify or construct percent-encoded strings.

Frequently Asked Questions

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Character

Encoded

␣

%20

%21

%22

%23

%24

%25

%26

%27

(

%28

)

%29

%2B

%2C

%2F

%3A

;

%3B

%3D

%3F

%40

%3C

%3E

How to Use the URL Encoder/Decoder

Choose your mode — Select Encode to convert text to percent-encoded format, or Decode to convert percent-encoded strings back to readable text. Click the mode buttons in the toolbar or use the dedicated Encode/Decode action buttons.

Select encoding type — When encoding, choose whether to encode the full URL (preserves structural characters like :// and ? using encodeURI) or encode values only (encodes everything including /, ?, and = using encodeURIComponent). Use full URL mode for complete web addresses, and values-only mode for query parameter values.

Enter your input — Type or paste your text into the input textarea on the left. For encoding, enter any text including URLs, query strings, or text with special characters. For decoding, paste a percent-encoded string.

Encode or Decode — Click the Encode or Decode button to process your input. Alternatively, enable the auto-encode toggle for real-time processing as you type. The result appears instantly in the output panel.

Copy or Swap — Click Copy Output to copy the result to your clipboard. Use the Swap button to move the output back to the input and flip the mode, useful for round-trip verification.

Features

Encode mode with two strategies: encodeURI() for full URLs and encodeURIComponent() for values

Decode mode using decodeURIComponent() to convert percent-encoded strings back to readable text

Full URL toggle to preserve structural URL delimiters (://, ?, &, =) when encoding complete web addresses

Auto-encode toggle for instant real-time processing as you type

Reference table of 20 common URL-encoded characters with hex values and descriptions

Stats bar showing input length, output length, and count of encoded/decoded characters

Swap button to quickly move output to input and flip between encode/decode modes

Clear error display for invalid percent-encoded input with specific guidance

Side-by-side layout on desktop, stacked layout on mobile for comfortable editing

100% client-side processing — your data never leaves your browser

Understanding URL Encoding

What is Percent Encoding?

encodeURI vs encodeURIComponent

Reserved vs Unreserved Characters

UTF-8 in URL Encoding

Common Use Cases

API Query Parameters

Encode parameter values when constructing API URLs to ensure special characters like spaces, ampersands, and equals signs don't break the query string structure.

Web Form Data

Understand how browsers encode form submissions and decode URL-encoded form data received from application/x-www-form-urlencoded POST requests.

URL Sharing and Links

Encode URLs that contain special characters before embedding them in emails, social media posts, or other contexts where the URL might be mangled.

Debugging API Requests

Decode percent-encoded URLs from browser dev tools, server logs, or API documentation to understand the actual parameter values being sent.

Redirect URLs

Encode redirect target URLs when passing them as query parameters (e.g., ?redirect=/page?a=1&b=2 must be properly encoded to avoid parsing errors).

SEO and Canonical URLs

Ensure URLs contain only safe ASCII characters for search engine crawlers. Non-ASCII characters in slugs should be percent-encoded for proper indexing.

Data URI Parameters

Encode data within data URIs or custom URL schemes where special characters could be misinterpreted as delimiters.

Webhook and Callback URLs

Encode callback URLs that contain query parameters when passing them as values in other query strings or configuration fields.

URL Encoder/Decoder Tips

If you need to encode binary data or authentication payloads for transmission, use our Base64 Encoder — it converts arbitrary data into a 64-character ASCII representation suitable for JSON, email, and data URIs.

When embedding user-generated text into HTML templates, first URL-encode it here, then use our HTML Entity Encoder to convert special characters like <, >, and & into entity references for XSS prevention.

If your encoded URL contains JSON query parameters, decode them first with this tool, then paste the result into our JSON Formatter to beautify and validate the structure.

Enable the 'Encode full URL' toggle when you have a complete URL with colons, slashes, and question marks that should be preserved as structural delimiters. It uses encodeURI() instead of encodeURIComponent(), keeping :///?= reserved characters intact.

The Swap button moves the output to the input area and flips between encode and decode modes — perfect for round-trip testing to verify your encoded strings decode back to the original text.

Enable auto-encode for instant feedback as you type. This is especially useful when working with API query strings where you want to see the encoded result in real time as you build parameter values.

Spaces in URLs are encoded as %20 by default (the RFC 3986 standard). Note that some legacy systems use + for spaces in application/x-www-form-urlencoded data — our tool always uses the standard %20 format.

The reference table below the tool shows 20 commonly encoded characters with their hex values. Use it as a quick lookup when you need to manually verify or construct percent-encoded strings.

Frequently Asked Questions