Code, APIs, debugging
Developer Tools
Fast browser tools for JSON, formatting, encoding, hashing, regex, timestamps, Firebase, Android, and daily developer workflows.
Collection includes
145
free tools, no signup
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Featured Developer Tools
JSON
JSON Viewer
Visualize and explore JSON data in a collapsible tree
Use tool ->JSON
JSON Formatter
Beautify or minify your JSON instantly
Use tool ->Developer
JSON to TypeScript Interface
Generate TypeScript interfaces from JSON objects and arrays with optional root interface name
Use tool ->Developer
JWT Decoder & Inspector
Decode JWT header, payload, expiry, and claims locally in your browser
Use tool ->Converter
Unix Timestamp Converter
Convert Unix timestamps, epoch time, UTC, local dates, and milliseconds instantly
Use tool ->Developer
Regex Tester
Test and debug regular expressions
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All tools in this collection
JSON
JSON Path Finder
Find and copy dot paths, bracket paths, and values from nested JSON objects and API responses
Use tool ->JSON
JSON Schema Generator
Generate JSON Schema from sample JSON with inferred types, required fields, arrays, and nested objects
Use tool ->Developer
Color Contrast Checker
Check WCAG color contrast ratio for text and background colors with preview and CSS output
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Base64 Encoder/Decoder
Encode and decode Base64 strings
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Image to Base64 Converter
Convert images to Base64 strings or Data URLs locally with preview, copy, and download
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Hash Generator
Generate MD5, SHA, and HMAC hashes from text or files
Use tool ->Formatter
SQL Formatter
Format, beautify, minify, and clean SQL queries online
Use tool ->Formatter
XML Formatter
Format, beautify, minify, and validate XML strings with copyable output
Use tool ->Formatter
HTML Formatter
Format or minify HTML markup for readable templates, snippets, and emails
Use tool ->Formatter
CSS Minifier
Minify CSS by removing comments, whitespace, and unnecessary formatting for smaller stylesheets
Use tool ->Formatter
JavaScript Minifier
Minify JavaScript snippets by removing comments, whitespace, and formatting for quick compact output
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CSS Specificity Calculator
Calculate CSS selector specificity, compare selectors, and find which rule wins
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URL Encoder/Decoder
Encode or decode URL strings
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URL Parser
Parse URLs into protocol, host, path, hash, query parameters, UTM tags, and copyable reports
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Color Converter
Convert between HEX, RGB, and HSL
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Password Strength Checker
Check password strength, entropy, crack-time estimate, and improvement tips locally
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HTTP Status Code Lookup
Look up HTTP status codes, meaning, category, and practical API debugging guidance
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MIME Type Lookup
Find MIME types by file extension or extension by MIME type for web uploads and headers
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HTTP Header Parser
Parse raw HTTP response headers, inspect cache, security, CORS, content type, and copy a readable report
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CSP Generator
Generate Content-Security-Policy headers for scripts, styles, images, fonts, frames, connections, and forms
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Security Headers Generator
Generate starter security headers for HSTS, CSP, frame protection, referrer policy, permissions policy, and MIME sniffing
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Redirect Rule Generator
Generate redirect rules for Vercel, Netlify, Next.js, Apache .htaccess, and Nginx from source and destination paths
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SPF Record Generator
Generate SPF TXT records for domain email with includes, IPv4, IPv6, MX, A, and all-policy options
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DMARC Record Generator
Generate DMARC TXT records with policy, reporting emails, alignment, percentage, and subdomain rules
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DNS Record Generator
Generate common DNS records including A, AAAA, CNAME, TXT, MX, and SRV with copy-ready zone-style output
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MX Record Generator
Generate MX records for business email providers with priority, host, TTL, and copy-ready DNS values
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User Agent Parser
Parse browser, OS, device type, rendering engine, and bot hints from a user agent string
Use tool ->Firebase
Firebase Cost Calculator
Estimate Firebase costs from Firestore, Hosting, storage, and traffic usage
Use tool ->Firebase
Firebase Rules Generator
Generate starter Firestore and Storage security rules
Use tool ->Android
Android Manifest Generator
Create AndroidManifest.xml snippets with permissions and deep links
Use tool ->Android
Deep Link Generator
Generate app links, Android intent URLs, and manifest intent filters
Use tool ->Firebase
FCM Payload Builder
Build Firebase Cloud Messaging JSON payloads for tokens, topics, and conditions
Use tool ->Android
Logcat Analyzer
Analyze Android logcat output for errors, warnings, crashes, and exceptions
Use tool ->Android
APK Size Analyzer
Inspect APK file size by category and largest ZIP entries
Use tool ->Android
Play Store Release Notes Generator
Generate Google Play release notes under the 500-character limit
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Page Speed Audit Checklist
Review images, JavaScript, fonts, layout shift, caching, third-party scripts, and Core Web Vitals improvements
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Mobile Usability Checklist
Check mobile spacing, tap targets, sticky headers, forms, tables, media, horizontal scroll, and tool usability
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Accessibility Audit Checklist
Review headings, labels, contrast, keyboard flow, focus states, alt text, form errors, and readable page structure
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Bug Report Template Generator
Create clear bug reports with steps to reproduce, expected result, actual result, environment, and severity
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Release Checklist Generator
Create a software release checklist for QA, backups, analytics, deployment, rollback, and post-launch checks
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API Requirements Template
Draft API requirements with endpoints, auth, payloads, errors, rate limits, webhooks, and testing notes
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Beta Testing Checklist
Create a beta testing checklist for devices, testers, builds, install links, feedback, and release readiness
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Test Case Generator
Generate practical test cases with scenario, steps, expected result, priority, device, and owner
Use tool ->Developer
App Feedback Form Builder
Build a tester feedback form for mobile apps with device, build, rating, bug, screenshot, and suggestion fields
Use tool ->Developer
App Store Listing Checklist
Create an app store listing checklist for title, screenshots, privacy, category, keywords, and release notes
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Crash Report Summary Template
Summarize crash reports with device, app version, frequency, stack trace, impact, and next debugging step
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Tester Invite Message Generator
Write clear beta tester invite messages with install link, QR note, testing scope, deadline, and feedback instructions
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QA Device Matrix Generator
Plan mobile QA coverage by device, OS, screen size, network, priority, owner, and testing notes
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Build Handoff Checklist
Create a mobile build handoff checklist with version, environment, install link, release notes, risks, and owners
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App Version Name Generator
Generate practical app version names, build numbers, release labels, and changelog headings
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iOS Provisioning Checklist
Create an iOS provisioning checklist for UDIDs, bundle ID, certificates, profiles, entitlements, and install issues
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Store Review Response Template
Draft factual App Store or Play Store review responses, rejection replies, and policy clarification notes
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Privacy Data Safety Checklist
Prepare app privacy, data safety, SDK, permission, and account deletion checks before store submission
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Phased Rollout Planner
Plan staged app rollout percentages, monitoring metrics, release gates, and rollback triggers
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UAT Sign-off Template
Create a clean user acceptance testing sign-off note with scope, tested flows, issues, and approval status
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Mobile App Test Plan Generator
Generate a mobile app QA test plan for platforms, devices, flows, regression, smoke testing, and UAT
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API Integration Checklist
Plan API integrations with auth, endpoints, payloads, rate limits, errors, webhooks, sandbox, and production checks
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Payment Gateway Integration Checklist
Prepare payment gateway integration checks for checkout, webhooks, refunds, security, reconciliation, and go-live
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Website Launch QA Checklist
Create a website launch QA checklist for SEO, forms, analytics, redirects, performance, security, and mobile testing
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Post-Launch Support Checklist
Plan post-launch support checks for monitoring, incidents, analytics, feedback, bug fixing, and handover
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Bug Triage Matrix
Prioritize bugs by severity, impact, frequency, workaround, owner, and release decision
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Release Announcement Template
Write release announcements with what changed, who benefits, action needed, rollout notes, and support links
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Domain Renewal Planner
Plan domain renewals with registrar, expiry date, DNS owner, auto-renewal, payment, lock status, and backup access
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Certificate Renewal Checklist
Prepare SSL certificate renewal with expiry, domains, validation method, deployment owner, monitoring, and rollback notes
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Bug Triage Checklist
Triage bugs by impact, severity, affected users, reproduction confidence, workaround, owner, and release decision
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Release Notes Checklist
Prepare release notes with new features, fixes, breaking changes, migration notes, known issues, and support links
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QA Sign-Off Email
Draft QA sign-off emails with tested scope, build version, issues, risks, exclusions, evidence, and approval request
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QA Test Plan Template
Create QA test plans with scope, environments, devices, test cases, data needs, blockers, signoff, and release risks
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Release Readiness Checklist
Review release readiness with QA, monitoring, rollback, docs, support handoff, approvals, and launch communication
Use tool ->Developer
Password Reset Checklist
Create a safe checklist for resetting account passwords, checking recovery email, enabling 2FA, and logging out old sessions
Use tool ->Developer
API Request Builder
Build a clean API request plan with method, endpoint, headers, body, auth notes, expected response, and test cases
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API Auth Checklist
Plan API authentication checks for tokens, scopes, expiry, refresh, storage, permissions, errors, and secret safety
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API Rate Limit Planner
Design API rate limit rules with quotas, windows, retry headers, user tiers, abuse protection, and client guidance
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API Pagination Checklist
Review API pagination behavior for limit, cursor, offset, sorting, empty states, next links, and stable results
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API Versioning Planner
Plan API versioning strategy, compatibility rules, migration docs, headers, URLs, deprecation, and client impact
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API Deprecation Notice Generator
Draft API deprecation notices with affected endpoints, timeline, migration path, support window, and client action steps
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Webhook Retry Policy Planner
Plan webhook retry behavior with attempts, backoff, signing, idempotency, delivery logs, dead-letter handling, and alerts
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Database Backup Checklist
Plan database backups with schedule, retention, encryption, restore testing, access control, alerts, and ownership
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Database Migration Rollback Plan
Prepare database migration rollback notes with backup timing, validation queries, cutover steps, owners, and stop conditions
Use tool ->Developer
Environment Variable Rollout Checklist
Safely roll out environment variables across local, preview, staging, and production without exposing secrets
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Log Retention Policy Planner
Plan log retention by data type, environment, privacy risk, storage cost, access, redaction, and deletion schedule
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Error Message QA Checklist
Review app error messages for clarity, recovery guidance, security leakage, tone, localization, and analytics safety
Use tool ->Developer
Dockerfile Review Checklist
Review Dockerfiles for base image choice, build cache, secrets, non-root user, health checks, size, and production safety
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Deployment Runbook Template
Create a deployment runbook with owners, steps, validation, rollback, communications, and monitoring checks
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CORS Policy Checklist
Review CORS rules for allowed origins, methods, headers, credentials, preflight, and production safety
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Cache-Control Checklist
Plan cache headers for HTML, APIs, images, assets, CDNs, stale content, and invalidation strategy
Use tool ->Developer
Cookie Consent QA Checklist
Review cookie consent flows for banners, categories, analytics, ads, regional behavior, and consent updates
Use tool ->Developer
Database Index Review Checklist
Review database indexes for slow queries, write impact, duplicates, migrations, monitoring, and rollback safety
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.env Example Generator
Create a safe .env.example outline with variable names, descriptions, defaults, and secret placeholders
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Webhook Signature Checklist
Review webhook signature verification with raw body handling, timestamp tolerance, replay protection, secret rotation, and logging safety
Use tool ->Developer
API Changelog Generator
Draft API changelog notes with added endpoints, changes, fixes, breaking changes, migration notes, and release dates
Use tool ->Developer
Incident Postmortem Template
Create a blameless incident postmortem with timeline, impact, root cause, detection, response, and action items
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Database Connection Pool Planner
Plan database connection pool limits for web apps, workers, serverless functions, queues, and production safety
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Dependency Update Checklist
Review dependency updates for changelogs, breaking changes, security patches, lockfiles, tests, and rollback
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npm Package Release Checklist
Prepare npm package releases with versioning, changelog, build output, package files, README, tags, and publish safety
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Go-Live Approval Checklist
Review launch readiness with QA, backups, DNS, analytics, rollback, owners, approvals, and communication plan
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Post-Launch Review Template
Create post-launch reviews with metrics, incidents, feedback, bugs, wins, lessons, and next action owners
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Change Freeze Checklist
Plan change freeze periods with blocked changes, exceptions, owners, deployment rules, rollback, and communication notes
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Access Log Review Checklist
Review access logs for unusual activity, admin actions, failed logins, exports, owner checks, and evidence notes
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Security Incident Communication Template
Draft security incident updates with known facts, impact, actions, timeline, owners, next update, and approval reminders
Use tool ->Developer
cURL Command Generator
Generate a readable cURL command outline from endpoint, method, headers, body, and auth notes
Use tool ->JSON
JSON String Escape
Escape or unescape JSON string values for API payloads, configs, tests, and code snippets
Use tool ->JSON
JSONL to JSON Array
Convert newline-delimited JSON records into one valid JSON array with validation
Use tool ->Developer
SQL IN Clause Generator
Convert pasted IDs, emails, SKUs, or names into a safe SQL IN clause
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CSV to SQL INSERT
Convert pasted CSV rows into SQL INSERT statements for seed data and demos
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Query String to JSON
Convert URL query parameters into clean JSON for debugging links, APIs, and UTM tags
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JSON to Query String
Convert a JSON object into an encoded URL query string with repeated array parameters
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Regex Escape Tool
Escape special regex characters so pasted text can be searched as a literal pattern
Use tool ->JSON
JSON Sort Keys
Sort JSON object keys alphabetically for stable diffs, configs, payloads, and snapshots
Use tool ->JSON
JSON Key Extractor
Extract JSON keys, paths, and value types from nested API responses and config files
Use tool ->Developer
ENV to JSON
Convert .env-style key-value lines into JSON for docs, scripts, and safe examples
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JSON to ENV
Convert JSON values into .env-style key-value lines with optional key prefix
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Properties to JSON
Convert Java .properties or key=value config files into JSON with validation notes
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JSON to Properties
Convert JSON objects into .properties style key-value lines with flattened nested keys
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INI to JSON
Convert INI config sections and key-value lines into JSON
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JSON to INI
Convert simple JSON objects into INI config text with sections
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ENV Diff Checker
Compare two .env-style files and find missing or changed keys without printing secret values
Use tool ->Developer
OpenAPI Path Snippet Generator
Generate OpenAPI YAML path snippets with method, parameters, request body, and responses
Use tool ->Developer
Postman Environment Generator
Create Postman environment JSON files with safe placeholder variables
Use tool ->Developer
API Response Example Builder
Build success and error response examples for REST API documentation
Use tool ->Developer
API Error Code Table Generator
Create Markdown API error code tables with status, code, message, and recommended fix
Use tool ->Developer
Webhook Payload Checklist
Plan webhook events, payload fields, signature verification, retries, and logging
Use tool ->Developer
IPv4 Subnet Calculator
Calculate IPv4 network, broadcast, subnet mask, wildcard mask, usable range, and host count
Use tool ->Developer
Common Port Lookup
Search common TCP and UDP ports for web, database, email, DNS, SSH, Docker, Redis, and more
Use tool ->Developer
Cache-Control Header Generator
Generate Cache-Control headers for static assets, HTML pages, APIs, and private responses
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CORS Header Generator
Create copy-ready CORS headers with origin, methods, headers, credentials, and preflight cache settings
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SSL Certificate Checklist
Prepare HTTPS, SSL certificate, redirect, mixed content, and renewal checks before launch
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Redirect Map Checker
Review old-to-new URL redirect maps for missing targets, loops, status codes, and SEO migration QA
Use tool ->Developer
URL Status Checklist
Create a URL QA checklist for 200 pages, redirects, 404s, canonicals, noindex, and mobile checks
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Launch Rollback Plan
Plan rollback triggers, owners, deployment steps, monitoring checks, and communication before release
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Set-Cookie Header Checker
Inspect Set-Cookie headers for Secure, HttpOnly, SameSite, Path, and common production safety notes
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Browser Storage Estimator
Estimate localStorage, sessionStorage, cookie, or IndexedDB payload size before storing browser-side data
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Accessibility QA Checklist
Create an accessibility QA checklist for keyboard use, focus states, labels, alt text, contrast, and mobile layout
Use tool ->Developer
Form QA Checklist
Prepare form testing checks for validation, required fields, success states, errors, integrations, and privacy
Use tool ->Developer
Mobile Responsive Checklist
Create a mobile UI QA checklist for spacing, tap targets, text wrapping, headers, modals, and tool usability
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DNS Migration Checklist
Plan DNS changes for hosting, email, CDN, TTL, verification records, HTTPS, and rollback before migration
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404 Page QA Checklist
Review 404 pages for status code, helpful recovery links, navigation, mobile layout, analytics, and SEO safety
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Page Speed Budget Planner
Set page weight budgets for JavaScript, CSS, images, fonts, third-party scripts, and mobile performance targets
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Website Launch Monitoring Checklist
Create a post-launch monitoring checklist for uptime, analytics, forms, errors, Search Console, speed, and rollback readiness
Use tool ->Developer
QA Test Case Generator
Generate manual QA test cases with preconditions, steps, expected results, edge cases, and regression notes
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