Formalint Developer Tools

Phone Number Regex ValidationValidate phone-shaped input without pretending regex can prove a reachable number. Password Regex ValidationDesign password checks that help users without creating fragile security theater. IP Address Regex ValidatorCheck IPv4 string shape before using network tools or address parsers. Slug Regex ValidatorKeep public URLs clean, readable and predictable. HEX Color Regex ValidatorCheck color strings before converting them into RGB or HSL. JavaScript Regex match vs testChoose the right JavaScript regex method before trusting a result. JSON Escape and UnescapeRead JSON string escaping without breaking valid payloads. JSON Lines and NDJSONDebug newline-delimited JSON exports without wrapping everything by instinct. curl POST JSON RequestBuild repeatable curl POST requests for JSON APIs without losing headers, body shape or auth context. HTTP Request MethodsUnderstand GET, POST, PUT, PATCH, DELETE, HEAD and OPTIONS before debugging API behavior. REST API Error ResponseDesign and debug consistent REST API error responses with status, code, message, details and correlation IDs. API Versioning StrategyPlan URL, header and media-type API versioning so client integrations do not break quietly. Webhook Signature VerificationVerify webhook signatures with raw bodies, timestamps, HMAC secrets and replay protection. OAuth Refresh Token DebuggingDebug refresh-token rotation, expired sessions, revoked grants and frontend retry loops. Regex Extract NumbersExtract integers, decimals, negative values and IDs from text while keeping parsing limits clear. Regex Remove Duplicate LinesClean repeated lines in logs, lists and copied text with regex-aware review notes. Regex Whitespace NormalizationNormalize spaces, tabs, blank lines and pasted text safely before validation or import. Regex Capture GroupsUse numbered groups, named groups and non-capturing groups without making extraction code fragile. JSON Merge PatchUnderstand partial JSON updates, null semantics and safer API PATCH request review. JSON Array FilteringInspect JSON arrays, missing fields, duplicates and filter assumptions before transforming data. CSV CleanupClean CSV headers, delimiters, quotes, blank rows and encoding issues before conversion to JSON. XML Namespace DebuggingDebug XML namespace prefixes, default namespaces and XPath surprises in integration payloads. YAML Docker ComposeReview Docker Compose YAML indentation, environment variables, ports, volumes and service blocks. SQL GROUP BY DebuggingDebug grouped SQL reports, aggregates, HAVING filters and missing dimensions. SQL Date Range DebuggingReview SQL date ranges, inclusive boundaries, timezones and index-friendly filters. PostgreSQL EXPLAIN ANALYZERead PostgreSQL query plans, row estimates, loops, timing and index usage safely. MySQL Processlist DebuggingUse MySQL processlist evidence to inspect active queries, locks, sleep sessions and incidents. Redis SLOWLOG DebuggingUse Redis SLOWLOG to inspect expensive commands, latency symptoms and cache misuse. Docker Volume DebuggingDebug Docker volumes, bind mounts, permissions, persistence and missing files. Kubernetes CrashLoopBackOffInvestigate CrashLoopBackOff with logs, events, probes, env vars and container exit codes. Linux systemctl DebuggingUse systemctl status, restart history, unit files and journal evidence during service incidents. Git Branch CleanupClean local and remote Git branches safely after merges, releases and abandoned experiments. PHP Composer Dependency ConflictDebug Composer version conflicts, platform requirements, lock files and package constraints. Java Maven Dependency DebuggingDebug Maven dependency trees, version conflicts, exclusions and build-classpath surprises. Email Regex PythonValidate email-shaped strings in Python while keeping deliverability and account rules outside regex. Email Regex PHPUse PHP email validation, regex checks and filter_var without turning format checks into business truth. Regex Word BoundaryUse word boundaries for tokens, IDs and search terms without surprising Unicode or punctuation behavior. Regex Multiline AnchorsUnderstand anchors, multiline flags and line-by-line matching before parsing copied logs. Regex URL ExtractionExtract URLs from logs, Markdown and pasted text while knowing when a real URL parser is safer. curl Headers DebuggingInspect request and response headers with curl before changing API clients, proxies or CORS settings. curl Bearer TokenTest bearer-token APIs with curl while redacting secrets and separating auth from payload errors. Postman to curl DebuggingTurn a Postman request into a repeatable curl command for tickets, terminals and CI evidence. API Request Body ValidationDebug JSON request-body validation, content types, required fields and schema mismatch errors. API Correlation ID LoggingUse correlation IDs to connect frontend errors, gateway logs, service logs and database evidence. JWT Signature VerificationVerify JWT algorithms, keys and signatures without exposing real tokens or trusting decoded claims blindly. JSON Path QueryUse JSON path thinking to inspect nested payloads, arrays and optional fields before transforming data. JSON null vs undefinedSeparate JSON null, missing fields and JavaScript undefined before debugging PATCH and schema behavior. XML XPath DebuggingDebug XPath selectors, namespaces, attributes and text nodes in XML integrations. YAML Anchors and AliasesUse YAML anchors, aliases and merge keys carefully in CI, Docker and infrastructure configuration. CSV UTF-8 EncodingDebug CSV encoding, delimiters, byte order marks and broken characters before imports. PostgreSQL Connection LimitInspect active PostgreSQL sessions, pool pressure and connection limits before restarting services. MySQL Deadlock DebuggingRead InnoDB deadlock evidence and transaction patterns before changing indexes or retry logic. Redis Key NamingDesign Redis key names that are searchable, safe to expire and easier to debug during incidents. Linux Disk Space DebuggingFind which filesystem, directory, container or log stream is consuming Linux disk space. Nginx Access Log AnalysisUse access logs to inspect status codes, latency, upstream behavior and suspicious traffic. Python pip RequirementsDebug requirements.txt, pip installs, package versions and virtual environment mismatches. PHP ini ConfigurationFind which php.ini file is active for CLI, FPM and web requests before changing settings. Java Classpath DebuggingDebug classpath, missing classes, duplicate jars and service runtime differences in Java apps. Node.js package.json ScriptsRead npm scripts, environment variables and build commands before debugging Node.js deployments. Content Security Policy DebuggingDebug CSP violations, script sources, nonce usage, reports and safe rollout steps without weakening browser security. HSTS PreloadReview HSTS headers, preload requirements, subdomain risk and HTTPS rollout checks before submitting a domain. CSRF Token DebuggingDebug CSRF token mismatches, SameSite cookies, forms, headers and cross-origin session flows. API Key RotationRotate API keys with inventory, staged rollout, logging, rollback and safe secret handling. Secrets Redaction ChecklistRedact tokens, passwords, connection strings and customer identifiers before sharing logs or payloads. Dependency Vulnerability TriageTriage dependency vulnerabilities by reachability, exploitability, version constraints and release risk. Secure Cookie ChecklistReview Secure, HttpOnly, SameSite, domain, path and expiration choices for web session cookies. GitHub Actions DebuggingDebug failed GitHub Actions jobs with logs, runners, checkout state, caches, secrets and matrix values. GitHub Actions Environment SecretsUse GitHub Actions secrets, variables and environments without leaking values into logs or builds. Docker Build Cache DebuggingDebug Docker build cache, layers, build args, context size and stale images in CI pipelines. CI Failing Tests DebuggingSeparate flaky tests, missing services, env drift, dependency changes and timeout failures in CI. Deployment Rollback ChecklistPrepare rollback evidence, database compatibility, feature flags and release notes before production deploys. Release Checklist for DevelopersShip safer releases with version notes, migrations, monitoring, smoke tests and support handoff. Log LevelsChoose debug, info, warn and error levels so production logs stay useful during incidents. Structured LoggingDesign JSON logs with correlation IDs, event names, user-safe fields and searchable incident context. Application Health CheckDesign health endpoints that separate liveness, readiness, dependencies and degraded service states. Uptime Monitoring ChecklistMonitor public endpoints, APIs, certificates and user-visible flows without creating noisy alerts. Error Budget and SLOUse SLOs and error budgets to explain reliability work, incidents and release risk. Cloudflare DNS DeploymentPrepare Cloudflare DNS, proxy mode, SSL settings, redirects and verification before launching a site. Vercel Environment VariablesDebug Vercel environment variables across preview, production and local development builds. Static Site Deployment ChecklistLaunch static sites with canonical URLs, sitemap, robots, HTTPS, analytics and cache checks. GitHub Pages Custom DomainConnect a custom domain to GitHub Pages with A records, CNAME, HTTPS and DNS propagation checks. SSL Renewal DebuggingDebug SSL renewal, certificate chains, DNS validation, rate limits and expired HTTPS endpoints. CDN Cache PurgePurge CDN cache safely while preserving user performance, asset versioning and rollout evidence. Robots.txt and Sitemap LaunchReview robots.txt, sitemap URLs, canonical targets and indexing signals before a public launch. Google Search Console IndexingReview indexing status, submitted sitemaps, canonical signals, crawl errors and page quality before requesting another Google review. Sitemap Lastmod StrategyUse sitemap lastmod dates honestly so crawlers can separate real content updates from unchanged static pages. Canonical URL DebuggingDebug canonical tags, duplicate URLs, index.html variants, trailing slash behavior and Search Console canonical mismatches. Robots Meta Tag DebuggingCheck robots meta tags, robots.txt rules and crawl directives before assuming Google ignored a new developer page. ads.txt DebuggingVerify ads.txt placement, publisher ID, HTTPS access, redirects and cache state before an AdSense site review. GitHub Pages Deployment LogUse GitHub Pages deployment evidence to verify what Google and users can actually reach after a static-site update. Browser Console DebuggingUse the browser console to capture JavaScript errors, CSP messages, failed resources and runtime context without guessing. DevTools Network Tab DebuggingRead request URLs, status codes, response headers, payloads and cache behavior from the browser Network tab. Source Map DebuggingUse source maps to connect minified production JavaScript errors back to readable files, functions and release commits. Core Web Vitals DebuggingDebug LCP, CLS, INP and page responsiveness with browser evidence instead of guessing from a single score. Lighthouse AuditTurn a Lighthouse report into practical fixes for performance, accessibility, SEO, best practices and static-site quality. JavaScript Error Stack TraceRead JavaScript stack traces by message, call order, async boundary, source file and release context. Developer Forum QuestionWrite developer forum questions with context, expected behavior, actual behavior, safe samples and a clear next step. Minimal ReproductionReduce a bug report to the smallest safe example that still proves the behavior another developer needs to inspect. Bug ReportUse a concise bug report structure for browser, API, database, formatter and deployment problems without leaking sensitive data. Code Review QuestionAsk code review questions that focus on behavior, risk, tests, edge cases and maintainability instead of personal preference. API Debugging ForumShare API debugging questions with method, endpoint, status, headers, safe payload shape and correlation evidence. Database Incident ForumAsk database incident questions with read-only evidence for sessions, locks, slow queries, storage, cache and timestamps. Community Moderation PolicyDefine Formalint forum rules for safe samples, respectful technical discussion, no secrets, no spam and practical developer help. Email Regex CheatsheetCompare practical email regex patterns, test cases and validation limits before using a pattern in forms, APIs or imports. Email Regex Test CasesUse a focused list of valid and invalid email samples to review regex behavior before shipping a form or API validator. Email Validation in JavaScriptValidate email input in JavaScript with clear client-side hints, safe trimming and server-side verification boundaries. Email Validation in TypeScriptModel email validation in TypeScript with typed results, reusable helpers and safe error messages for frontend and API code. Email Validation in PHPValidate email addresses in PHP with filter_var, regex fallback rules and safe handling for forms, imports and logs. Email Validation in PythonValidate email input in Python services with simple syntax checks, normalization notes and batch import safeguards. Email Domain DNS ValidationCheck email domains with DNS-aware validation boundaries, MX expectations and safe fallback behavior for signup flows. Disposable Email DetectionPlan disposable email checks as a product policy layer instead of confusing them with basic email regex validation. XML Lint ErrorDecode common XML lint errors, line-column messages, malformed tags, escaping mistakes and namespace problems before fixing production payloads. XML Well-Formed vs ValidUnderstand the difference between well-formed XML syntax and schema-valid XML before debugging integrations, feeds or SOAP messages. YAML Lint ErrorFix YAML lint errors caused by indentation, list nesting, tabs, duplicate keys and confusing scalar values in config files. YAML CI LintingAdd YAML lint checks to CI without blocking teams on noisy style rules or leaking environment configuration. SQL Cleanup ChecklistClean messy SQL before review by separating formatting, joins, filters, aliases, parameters and performance-sensitive changes. SQL Query Formatting ReviewReview formatted SQL by checking readability, data scope, execution risk and safe examples instead of only whitespace style. JSON Lint ErrorFix JSON lint errors around trailing commas, invalid quotes, comments, escaping, arrays and object shape before API debugging. Config File ValidationValidate JSON, YAML, XML, env and INI-style configuration files with syntax checks, schema rules and deployment-safe review steps. All-in-One Developer WorkspaceFormat JSON, inspect trees and use instant regex, epoch, URL and SHA-256 utilities in one local-first browser workspace. API Schema Drift DebuggingDetect API schema drift when fields, types, nullability or nested response shapes change without a coordinated client release. API Retry and Exponential BackoffDesign API retries with exponential backoff, jitter, attempt limits and idempotency boundaries instead of multiplying an outage. API Rate Limit HeadersInterpret 429 responses, Retry-After and common rate-limit headers while keeping client throttling observable and predictable. Webhook Replay DebuggingReplay webhooks safely with captured metadata, idempotent handlers, signature-aware fixtures and observable delivery outcomes. API HMAC Request SigningDebug HMAC request signatures by making canonical input, body bytes, timestamps and constant-time verification explicit. cURL TLS DebuggingUse cURL verbose output to separate DNS, TCP, certificate chain, hostname, protocol and proxy failures without disabling verification. OpenAPI Breaking Change ChecklistReview OpenAPI changes for removed operations, stricter inputs, response shape drift and generated-client impact before release. API Error Response DesignDesign stable API error responses with machine-readable codes, safe messages, field details, correlation IDs and retry guidance. Regex ToolkitLearn regex fundamentals, then test email, URL, UUID, date and log patterns in the matcher. Data Format ToolsCompare JSON, XML and YAML, then format or lint the payload you are working with. API DebuggingUse status codes, headers, payload checks and incident notes to reduce guesswork. curl API DebuggingCapture headers, JSON payloads, auth, timing, redirects, TLS and preflight evidence. OAuth JWT DebuggingSeparate 401, 403, scopes, issuer, audience, expiration and refresh-token failures. OpenAPI Contract ChecklistReview paths, operations, parameters, schemas, responses, examples and auth rules. Webhook DebuggingDebug deliveries, signatures, retries, idempotency, raw bodies and queue handoff. API Pagination DebuggingInspect Link headers, cursors, offsets, missing results and duplicate rows. API Idempotency and RetryDesign safe retries, idempotency keys, duplicate POST handling and timeout recovery. GraphQL API DebuggingInspect queries, variables, operation names, partial data and GraphQL error paths. Cookie SameSite DebuggingFix Secure, HttpOnly, SameSite, credential and session cookie failures. CORS Debugging GuideDebug origins, OPTIONS preflight, credentials, allowed headers and browser console errors. 429 Rate Limit DebuggingInspect Retry-After, RateLimit headers, quotas, backoff and throttled clients. HTTP Cache-ControlChoose safe cache headers for HTML, APIs, CDN responses and versioned assets. HTTP Security HeadersCheck CSP, HSTS, nosniff, frame protection, referrer policy and permissions policy. Data ValidationPlan client, server and integration validation before relying on a formatter alone. Formatter vs LinterUnderstand when you need formatting, linting, validation, parsing or schema checks. How Formalint WorksRead how local-first processing, analytics, ads and safe sample rules fit together. DBA Admin RoadmapUse a practical path for access, backups, restore tests, monitoring and incidents. Terminal WorkflowsChoose CMD, PowerShell, Git Bash or Linux shell before debugging a host. Docker Compose DebuggingInspect services, logs, ports, volumes, healthchecks and rebuilds safely. PostgreSQL DBA ChecklistUse psql, sessions, locks, sizes and backup checks before tuning SQL. MySQL DBA ChecklistInspect processlist, InnoDB, slow logs, backups and service state. Redis Debugging ChecklistCheck connectivity, memory, keyspace, clients, slowlog and latency safely. Nginx Reverse ProxyDebug upstreams, headers, TLS, redirects, logs and API gateway behavior. PHP Runtime ChecksInspect PHP CLI, FPM, Composer, extensions, php.ini and web server behavior. Java Runtime ChecksInspect JDK, JAVA_HOME, Maven, Gradle, JVM flags and service behavior. Python Runtime ChecksInspect Python, pip, venv, package paths, services and web worker behavior. Node.js Runtime ChecksInspect Node, npm, lockfiles, scripts, ports, PM2 and service logs. Hardware DiagnosticsRule out CPU, memory, disk, IO and network pressure before blaming code. Email Regex JavaScriptPractical email regex JavaScript guide with realistic validation rules, examples, edge cases and safe production advice. JavaScript Regex CheatsheetJavaScript regex cheatsheet for flags, anchors, groups, character classes, quantifiers, replacement and validation patterns. Lookahead LookbehindRegex lookahead and lookbehind guide for positive assertions, negative assertions, browser support thinking and safer examples. Regex ReplaceRegex replace guide for JavaScript string cleanup, capture groups, named groups, whitespace normalization and safe migrations. Regex PerformanceRegex performance guide for slow patterns, backtracking risk, large logs, input limits and safer parser choices. XML Schema XSDXML Schema XSD guide for validating XML structure, elements, attributes, namespaces and integration contracts. XML to JSON GuideXML to JSON conversion guide for attributes, arrays, namespaces, text nodes and safe API migration notes. YAML Lint ChecklistYAML lint checklist for indentation, tabs, anchors, quoted strings, booleans and CI configuration review. Docker Env FilesDocker env file guide for Compose variables, quoting, secrets boundaries, defaults and deployment debugging. Kubernetes Pod DebuggingKubernetes pod debugging guide for Pending, CrashLoopBackOff, ImagePullBackOff, logs, events and kubectl describe evidence. DNS DebuggingDNS debugging guide for A, CNAME, TXT, MX, nameservers, propagation, TTL and domain launch checks. TLS Certificate DebuggingTLS certificate debugging guide for HTTPS failures, redirects, certificate names, expiry, chains and mixed content. Nginx 502 504Nginx 502 and 504 debugging guide for upstream health, proxy timeouts, logs, DNS, TLS and gateway ownership. PowerShell Network DebuggingPowerShell network debugging guide for ping, TCP port tests, DNS, routes, services and Windows API connectivity. Git Merge ConflictsGit merge conflict guide for reading conflict markers, choosing changes, testing the result and finishing merges safely. Git Rebase WorkflowGit rebase workflow guide for updating branches, resolving conflicts, continuing safely and avoiding history surprises. PostgreSQL LocksPostgreSQL lock debugging guide for blocked sessions, pg_stat_activity, pg_locks, transactions and safe incident notes. PostgreSQL IndexesPostgreSQL index debugging guide for EXPLAIN, missing indexes, unused indexes, row estimates and safe query review. MySQL Slow QueriesMySQL slow query debugging guide for slow query log, EXPLAIN, indexes, lock time, rows examined and safer tuning notes. npm Dependency DebuggingNode.js npm dependency debugging guide for package-lock, npm install, npm ci, scripts, engines and module resolution. PHP Composer AutoloadPHP Composer autoload debugging guide for vendor files, namespaces, class maps, optimized autoload and deployment checks. Java Memory DebuggingJava memory debugging guide for heap settings, OutOfMemoryError, container limits, GC logs and JVM runtime evidence. Editorial PolicyReview how Formalint writes, updates and separates content from advertising. ChangelogTrack newly added tools, guides, quality updates and site improvements.