IP address calculatorCalculate an IPv4 subnet mask, network, broadcast address and usable host range from CIDR.
User-Agent parserInspect a user-agent string for browser, engine, OS, device class and bot-like markers.
URL parserInspect and edit URL components, or build campaign links from CSV with batch UTM parameters, collision checks and export.
Unicode character lookupInspect Unicode code points, UTF-8 bytes and UTF-16 escapes without a character-name database.
Regular expression libraryBrowse reusable regex examples with descriptions, flags and sample strings.
JSON Mock rule engineGenerate repeatable Mock JSON locally from field rules, types, ranges, and choices
Environment variable converterConvert .env and JSON, compare environment variables locally, and export a placeholder-only .env.example.
Cron expression readerExplain a five-field cron expression with a summary and per-field descriptions.
HTTP status code tableLook up HTTP response codes from 1xx to 5xx by number, English phrase or translated meaning.
Sitemap XML generatorBuild sitemap.xml from URL lines with optional modification dates, frequency and priority.
OpenAPI validator, diff and browserValidate, compare and browse OpenAPI locally, or convert OpenAPI and Postman 2.1 collections with explicit authentication, script and schema loss reports.
Protobuf encoder and decoderEncode schema-aware JSON to Protobuf, decode binary/Hex/Base64, and inspect wire fields locally
SQL Schema converter, ER and migration diffConvert SQL schemas, draw ER diagrams, compare two schemas and review dialect-specific migration drafts locally
GraphQL validator and formatterValidate SDL and GraphQL operations, fragments and variables locally; format documents and browse types
cURL to code converterConvert one cURL command locally into JavaScript Fetch, Python Requests, or Go net/http code, with explicit syntax limits and optional credential redaction.
Internationalization file checkerCompare locale JSON keys, types, placeholders and a declared flat ICU plural subset locally, with located issues and a complete JSON report.
HAR viewer & sanitizerInspect HAR requests, headers, bodies and timings locally, filter by domain or status, and export a configurable redacted archive for manual review.
HTTP response header analyzerParse pasted HTTP response headers locally, preserve repeated fields, and review caching, content type, redirects, CORS and security-header guidance.
Cookie / Set-Cookie parserInspect pasted Cookie request headers or Set-Cookie response headers locally, retain repeated entries and attributes, and export value-masked JSON by default.
Docker run to Compose converterConvert a supported Docker run command into Compose YAML locally, with environment values masked by default and explicit compatibility warnings.
Compose static validatorValidate Compose YAML locally against a pinned official schema and inspect located structure, service-reference and port diagnostics without running containers.
SemVer range testerTest a version list against npm SemVer ranges locally, with explicit prerelease matching, invalid-row detection and sorted matches that preserve build metadata.
package.json diffCompare dependency sections, scripts, engines and metadata in two package.json files locally, with clear moves and complete JSON export.
.gitignore rule testerTest one root .gitignore against sample paths locally, with ordered exceptions, excluded-parent explanations and matching rule lines.
chmod permission calculatorConvert octal and nine-character Unix permission strings locally, including setuid, setgid and sticky bits, with file and directory explanations.
JSON Schema validatorValidate JSON against Draft 7, 2019-09 or 2020-12 schemas locally, with local references, worker timeouts and paths-only diagnostics.
CSS Grid / Flex Layout GeneratorVisually set Grid columns or Flex direction, wrapping, gaps and alignment, then preview the layout and copy compact HTML/CSS.
Batch UTM link builderAdd campaign parameters from CSV, check existing UTM collisions and duplicate keys, preview every row and export safe CSV.