ToolKit

Network & Web Tools

Free Online Network & Web Tools

Browser-based utilities for web and network work. Encode and decode URLs, calculate subnet ranges, look up HTTP status codes, generate nginx redirects, and parse user-agent strings — all locally with no data sent to a server.

URL Encoder / Decoder
Encode and decode URLs instantly
Live
HTTP Status Code Reference
Quick reference for all HTTP status codes
Live
IP / CIDR Calculator
Calculate subnet ranges, masks and hosts
Live
Nginx Redirect Generator
Generate Nginx redirect configs instantly
Live
MIME Types Reference
Searchable MIME type and file extension lookup
Soon
Robots.txt Generator
Generate robots.txt files for your site
Soon
User-Agent Parser
Parse and decode browser user-agent strings
Soon
.htaccess Generator
Generate Apache .htaccess rules
Soon

Network and web tools for developers

Web development involves constant juggling of URLs, HTTP codes, subnet ranges, and server configuration files. Having a reliable reference and generator for each of these reduces errors and speeds up debugging.

URL encoding is one of the most misunderstood web concepts. RFC 3986 defines which characters must be percent-encoded in a URL — and the rules differ between the path component, the query string, and fragment identifiers. The URL encoder on this page applies the correct rules for each context.

Subnet calculation is a common point of friction for developers who work with cloud infrastructure. CIDR notation like 10.0.0.0/24 is compact but requires mental math for ranges and host counts. The IP/CIDR calculator decodes every field instantly.

Network & Web best practices

Encode query values, not full URLs
URL-encode individual query parameter values, not the entire URL. Encoding & or = in the wrong place breaks the query string structure. Use encodeURIComponent() in JavaScript, not encodeURI().
Know your 4xx vs 5xx codes
4xx errors are client mistakes (bad URL, missing auth, wrong method). 5xx errors are server failures. A 404 means the resource was not found — a 503 means the server is overwhelmed. Monitoring systems should alert differently for each.
Use /16 subnets for VPCs by default
A /16 gives 65,536 addresses — enough to subdivide into many /24 subnets (256 each) for different services and environments. Start broad and subnet down rather than starting too narrow.
Prefer 301 for permanent redirects
A 301 redirect is permanent — browsers cache it indefinitely. Use 301 only when you are certain the old URL will never be needed again. Use 302 or 307 while testing redirects, then switch to 301 when confirmed.

FAQ

Common questions

What is the difference between encodeURI and encodeURIComponent?

encodeURI() encodes a full URL, leaving characters like /, ?, & and = untouched. encodeURIComponent() encodes a value to be embedded in a URL, encoding those characters too. Always use encodeURIComponent() for individual query values.

What is CIDR notation?

CIDR (Classless Inter-Domain Routing) notation describes a network address and its subnet mask in one compact form: IP/prefix-length. 192.168.1.0/24 means the first 24 bits are the network — giving 256 addresses (254 usable hosts).

What HTTP status code means "try again later"?

503 Service Unavailable means the server is temporarily down. The Retry-After header can specify when to try again. 429 Too Many Requests is the rate-limiting equivalent — your client is sending too fast.

What is a user-agent string?

A user-agent string is sent by browsers and HTTP clients in every request. It identifies the browser, version, operating system, and rendering engine. Web servers use it for analytics, content negotiation, and bot detection.

What is the difference between robots.txt and a noindex meta tag?

robots.txt tells crawlers which URLs not to crawl. A noindex meta tag tells crawlers not to index a page in search results even after crawling it. If you want a page out of Google, use noindex — robots.txt alone does not remove existing indexed pages.

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