Network & HTTP Tools
Free online network, HTTP and API-schema tools — parse HTTP headers and status codes, URLs, IPv4 subnets, MAC addresses, user agents and MIME types, convert curl to code, and generate Protobuf, GraphQL and OpenAPI definitions from a sample response. All client-side.
15 free network & http tools — all browser-based
HTTP Headers Parser
Parses raw HTTP request or response headers (from curl -I, DevTools, or any HTTP client) into a categorized table.
HTTP Status Codes
A searchable reference of standard HTTP status codes with their meaning, color-coded by class (1xx-5xx)..
URL Parser
Breaks a URL down into protocol, host, port, path, and hash, and lets you inspect and edit query string parameters with the result URL updating live..
IPv4 Subnet Calculator
Calculates network address, broadcast address, subnet mask, wildcard mask, usable host range, and host count from an IPv4 address and CIDR prefix..
IP Address Extractor
Extracts every IPv4 and IPv6 address from pasted text, logs, or configs using practical regex patterns that handle compressed (::) and IPv4-mapped IPv6 forms, with optional deduplication and family filtering.
MAC Address Lookup
Validates a MAC/EUI-48 address, normalizes it between colon, hyphen, dot, and unseparated notations, and looks up the Organizationally Unique Identifier (OUI) vendor from a built-in table.
User Agent Parser
Parses any HTTP User-Agent string and breaks it down into browser, rendering engine, operating system, and device type with version numbers.
MIME Type Lookup
Looks up the MIME type for any file extension or reverse-lookup extensions by MIME type, with instant search and click-to-copy across common web file formats (images, audio, video, fonts, documents, archives)..
cURL to fetch()
Parses a curl command (method, headers, body, basic auth) and converts it into an equivalent JavaScript fetch() snippet..
JSON to Protobuf Schema
Generates a proto3 .proto file from a JSON sample, mapping values to int32, int64, double, bool and string, nesting message definitions for objects, marking arrays as repeated, assigning sequential field numbers, and converting keys to the lower_snake_case that the protobuf style guide requires, useful for bootstrapping gRPC service contracts from an existing REST payload..
JSON to GraphQL Schema
Generates GraphQL SDL type definitions from a JSON sample, mapping values to Int, Float, Boolean, String and ID, nesting object types, wrapping arrays as list types, marking non-null fields with an exclamation mark, and optionally emitting matching input types, useful for turning an existing REST response into a schema-first GraphQL API..
JSON to OpenAPI Schema
Generates an OpenAPI 3.1 / JSON Schema component from a JSON sample, inferring type and format (int32, int64, double, date-time, email, uri, uuid), describing arrays through their item schema, listing required properties, and emitting either YAML or JSON, useful for documenting an undocumented endpoint or seeding a components/schemas block in a Swagger file..
Content Security Policy Generator
Builds a Content-Security-Policy header from per-directive source lists, with presets for a strict nonce-based policy, a report-only rollout and a permissive starting point, warning about the combinations that silently defeat the policy such as unsafe-inline alongside a nonce, and emitting the header, a meta tag and an nginx add_header line..
Cache-Control Header Generator
Builds a Cache-Control header from cacheability, freshness and revalidation options, with presets for immutable fingerprinted assets, HTML that must always revalidate, private user data and no-store responses, showing the resulting max-age in human-readable form and explaining what each directive tells the browser versus a shared CDN cache..
robots.txt Tester
Tests whether a URL path is allowed for a given crawler by applying the robots.txt matching rules Google uses.
Debugging HTTP
The HTTP Headers Parser breaks raw headers into name/value pairs, and HTTP Status Codes is a quick reference for response codes.
Convert curl commands to fetch, Axios or language-specific code with curl to Code.
IP and URL inspection
The IPv4 Subnet Calculator computes network, broadcast and host ranges from a CIDR block.
The URL Parser decomposes any URL into its protocol, host, path, query and fragment components.
Frequently asked questions
Does the curl to code converter support authentication headers?
Yes. It translates -H header flags, -X method, -d data and auth into the target client's equivalent syntax.