Elysia Tools
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Tools
Developer utilities, networking, web debugging, and automation helpers
Calculators, numerics, date logic, statistics, and finance tools
Image, audio, and video processing, conversion, and optimization tools
Color, layout, graphics, visual styling, and design helper tools
Writing, cleanup, formatting, extraction, and text analysis tools
Format, file, archive, unit, and encoding conversion tools
Network
Parse RFC 8288 Link headers with the spec appendix-B algorithm, resolve relative URI-references against a base URL, classify rel types against the IANA registry, validate preload/prefetch hints, and simulate how a rel="next" pagination crawler walks your responses — including cycle detection.
Development
Test java.util.regex patterns online: (?<name>…) named groups, possessive quantifiers and atomic groups, Pattern flags, ASCII vs UNICODE_CHARACTER_CLASS \d semantics, and ready-to-paste Java code.
Analyze Cache-Control directives, calculate browser/shared-cache TTL and stale budgets, detect directive conflicts, and compare static behavior notes for generic HTTP, Fastly, Cloudflare, and Akamai.
Compare two JSON payloads and render a visual HTML diff with path-level additions, removals, changes, and statistics
Compress HTML by removing comments, collapsing whitespace and minifying inline CSS/JS
Dissect the HTTP/3 over QUIC handshake byte-by-byte. Visualise the 1-RTT fresh handshake, session-ticket resumption, and 0-RTT early-data scenarios, with sequence diagrams, per-packet field layouts, the Retry packet, and a side-by-side comparison against TCP + TLS 1.3. Built for interview prep, protocol learning, and performance engineering.
An interactive JSONPath REPL that runs multi-step query pipelines against any JSON. Write one JSONPath expression per line (e.g. $..book[?(@.price<10)] then $[0:5]) and see each step's matches with counts, paths, and values — plus a shareable URL that encodes your data and pipeline. Supports recursive descent ($..), wildcards ([*]), filters ([?(@.price<10)]), slices ([0:5:2]), and negative indices.
An in-browser GraphQL client: write queries and variables, send them to any GraphQL endpoint, and inspect formatted JSON results or error arrays — perfect for iterating on schemas during development
A lightweight in-browser HTTP client (mini Postman): send GET/POST/PUT/DELETE requests with custom headers and body, inspect status, headers, timing, and formatted response — all from your browser
Convert JSON data into C# classes with PascalCase properties, JsonPropertyName attributes, and nested type inference
Convert JSON data into Go struct definitions with json struct tags, exported PascalCase fields, and nested type inference
Convert JSON data into Java classes with Jackson @JsonProperty annotations, private fields, getters, and setters