Lightweight, Free & Private Web Utilities
Engineered for developers, sysadmins, testers, and digital commerce. Access instant disposable inboxes, real-time merchant fee currency calculators, deep DNS diagnostics, and lightning-fast terminal CLI options with zero tracking and zero telemetry.
Query instant ASCII diagnostics directly from bash, zsh, or terminal
curl https://bestutilities.org/ip2600:383:1a88:5d22:84fa:639e:d4a2:4f1d # View full visual IP geolocation, WebRTC LAN probe & interactive map: # https://bestutilities.org/my-ip
wget -qO- and http (HTTPie).Reserved banner container configured with strict Core Web Vitals CLS = 0 layout preservation.
Portal Directory Index
Select a specialized web utility below to launch the standalone client application.
One-Click Domain & Mail Health Report
Run parallel asynchronous checks on A, AAAA, MX, SPF, DKIM, DMARC, BIMI, MTA-STS, and DNSSEC. Generates weighted letter grades (A+ to F) and step-by-step remediation plans.
- Parallel 9-point asynchronous DNS & mail stack verification
- Weighted letter grading (A+ through F) & visual scorecards
- Step-by-step DNS record remediation code snippets
- One-click audit report export (Markdown, Jira, Plaintext, PDF)
Deliverability Readiness Score (Google & Yahoo)
Audit domain compliance with Google and Yahoo bulk sender requirements. Checks DMARC enforcement, SPF 10-lookup limits, DKIM signing, and RFC 8058 one-click unsubscribe headers.
- Strict Google & Yahoo 2024 bulk sender requirement auditor
- SPF lookup counter budget & DMARC policy enforcement test
- RFC 8058 List-Unsubscribe header validator and generator
- Postmaster Tools complaint rate compliance threshold advice
Hardened Postfix & Dovecot Config Builder
Interactive wizard to generate hardened main.cf and master.cf configuration files. Includes submission port 587, modern TLS ciphers, milters, and anti-spam rate limits.
- Hardened Postfix main.cf and master.cf configuration generation
- Modern TLS cipher suites (TLSv1.2/1.3) & Let's Encrypt integration
- Integrated Milter support for OpenDKIM, OpenDMARC & Rspamd
- Client rate limiting & anti-abuse anvil daemon settings
Nginx & Caddy Reverse Proxy Generator
Generate production-grade reverse proxy configurations with WebSocket upgrades, Let's Encrypt SSL termination, HSTS security headers, rate limiting, and Caddyfile syntax.
- Hardened Nginx reverse proxy virtual host configuration
- WebSocket upgrade headers (Connection & Upgrade) handling
- Certbot automated Let's Encrypt certificate acquisition script
- Equivalent Caddyfile syntax generator tab
Systemd Service & Timer Generator
Web form that outputs syntactically correct service.service and timer.timer systemd unit files with security sandboxing, auto-restart policies, and resource limits.
- Production-ready systemd .service and companion .timer generation
- Strict security sandboxing (ProtectSystem=strict, NoNewPrivileges)
- Automatic restart policies with restart delay timing
- One-click Linux deployment shell installation script
DNS Zone File & Cloudflare CSV Exporter
Convert live DNS records or raw text lines into compliant RFC 1035 BIND zone files and Cloudflare DNS import CSV format for instant zero-error migration.
- RFC 1035 compliant BIND zone file ($ORIGIN, $TTL, SOA, NS, MX, TXT)
- Cloudflare DNS import CSV table exporter
- Live DNS-over-HTTPS query auto-population
- One-click file download & copy to clipboard
Temporary Disposable Email
Generate instant disposable inboxes with custom alias selection, 3-7 day retention lifecycle, live auto-refresh, and full RFC 5322 header inspection. Built for automated software QA and anti-spam privacy.
- Instant alias generation on multiple domains
- Configurable retention: 3, 5, or 7 days
- Raw RFC 5322 MIME headers modal
- Automatic database purge & zero IP logs
Currency & Payment Fee Converter
Real-time interbank FX calculator combined with an advanced cross-border merchant fee engine. Accurately deduct payment gateway cuts (Stripe, PayPal, Wise) and FX spreads to calculate exact net take-home earnings.
- 1-hour cached interbank mid-market FX feeds
- Support for USD, EUR, GBP, COP, MXN, BRL & more
- Pre-configured processor presets (Stripe, PayPal, Wise)
- Mathematical fee breakdown & equation transparency
Email Header & Hop Latency Analyzer
Parse RFC 5322 email headers chronologically from bottom to top. Calculate exact latency deltas across Mail Transfer Agents (MTAs), isolate stalled delivery relays (>60s), and audit SPF, DKIM, DMARC, and TLS cipher levels.
- Bottom-to-top reverse chronological Received header parser
- Visual latency timeline with bottleneck delay flags
- SPF, DKIM, DMARC pass/fail cryptographic verification
- Originating IP extraction & RFC 1918 private subnet checks
Quick PCAP & Packet Dump Viewer
Client-side packet capture analyzer. Drop small .pcap or .pcapng files to instantly decode protocol bandwidth distributions, top talker endpoints, and plaintext HTTP/FTP security exposures with zero server upload.
- 100% in-browser ArrayBuffer binary packet decoding
- Bandwidth breakdown for DNS, HTTPS, SSH, NTP, and HTTP
- Clear warnings for unencrypted plaintext protocols
- Copyable 1-line capture commands for Windows, Mac & Linux
Network Ping & Latency Jitter Test
Real-time latency jitter and bufferbloat grader. Measures RFC 3550 packet variance, standard deviation over time, and packet drop percentages to evaluate connection quality for competitive gaming and VoIP calls.
- Real-time SVG latency timeline and jitter graph
- RFC 3550 Interarrival Jitter calculation (ms)
- Bufferbloat grade assessment (A+ to F)
- Suitability ratings for Zoom, Teams, and online gaming
My IP Dashboard & Geolocation Map
Detect your public WAN IP, probe internal private LAN interfaces via WebRTC ICE candidates, and view your ISP Point of Presence on an interactive OpenStreetMap.
- Public WAN IP detection with IPv4/IPv6 classification
- Client WebRTC ICE candidate local LAN probe & RFC 8828 mDNS status
- Interactive Leaflet OpenStreetMap centered on ISP PoP coordinates
- Autonomous System (ASN), ISP organization & reverse DNS PTR validation
Visual Route Tracer & Map
Trace multi-hop router paths across the global Internet backbone. Inspect intermediate TTL packet drops, measure hop latency, and map geographical paths on OpenStreetMap.
- Multi-hop router traceroute path mapping with Leaflet polyline overlay
- Hop latency indicators & ICMP TTL rate-limiting drop explanation (* * *)
- Geographic coordinates, reverse DNS PTR hostnames & BGP transit ASNs
- Total transit distance calculation in kilometers and miles across globe
Wi-Fi Channel & Subnet CIDR Planner
Calculate usable IPv4 host scopes, network masks, and wildcard boundaries. Features an interactive visual IP reservation map for static devices vs. dynamic DHCP pools and 2.4/5 GHz non-overlapping Wi-Fi channel planning.
- CIDR prefix bitwise subnet calculation (/8 through /30)
- Interactive visual IP allocation map (Gateway, Static, DHCP, IoT)
- 2.4 GHz non-overlapping channel map (Rule of 1, 6, 11)
- Binary subnet mask decomposition & RFC 1918 guidance
My System Specs & Hardware Diagnostics
Instant in-browser hardware profiler. Detect your unmasked WebGL GPU model, logical CPU core count, dynamic screen refresh rate (Hz), RAM memory tier, and OS build with 1-click Markdown export.
- Unmasked GPU renderer detection (NVIDIA, AMD, Apple, Intel)
- Logical CPU concurrency and thread capability
- Dynamic display refresh rate calculation (60, 120, 144 Hz)
- Export as Markdown Report for technical support & Discord
DORA Metrics & Cycle Time Benchmark Calculator
Benchmark your engineering velocity and reliability against Google DORA standards. Score Deployment Frequency, Lead Time for Changes, Change Failure Rate, and MTTR with actionable remediation steps.
- State of DevOps Elite/High/Medium/Low maturity classification
- Dual Throughput vs. Stability scorecard with percentile ranking
- Actionable engineering remediation roadmap per metric
- 1-click Export to Markdown for Jira, Confluence, and QBRs
Browser & Identity Consistency Checker
Client-side privacy and fingerprint audit. Probe for WebRTC public IP leaks, analyze User-Agent Client Hints, verify timezone integrity, and detect anti-spoofing heuristics.
- WebRTC STUN candidate leak probe for public & local IPs
- Dual User-Agent vs. Chromium Client Hints comparison
- Profile consistency check flagging spoofed OS & touch digitizers
- 1-click Export Privacy & Security Report in Markdown
Canvas & Audio Fingerprint Hash Generator
Generate cryptographic SHA-256 hashes of HTML5 Canvas 2D sub-pixel rendering and Web Audio dynamics compressor equations. Detect anti-fingerprint noise injection in real time.
- Sub-pixel canvas 2D anti-aliasing text and polygon hash
- Web Audio API dynamics compressor DSP waveform hash
- Real-time noise injection detection (Brave Shields / Canvas Defender)
- 1-click Export Hardware Hash Report in Markdown
Keyboard Rollover & Switch Chatter Tester
Interactive 100%, TKL, and 60% keyboard rollover test. Diagnose simultaneous anti-ghosting limits (NKRO), detect faulty mechanical switch chatter (<25ms debounce bounce), and test switch latency.
- Interactive ANSI virtual board with 100%, TKL, and 60% layouts
- Simultaneous N-Key Rollover (NKRO) ghosting tracker
- Mechanical switch chatter detector (<25ms bounce threshold)
- Synthesized click audio & 1-click Markdown diagnostic report
Gamepad & Joystick Drift Tester
Precision joystick drift diagnosis and controller testing. Features dual X/Y radar oscilloscopes, 360° circularity error benchmark, analog trigger travel percentage (0-100%), and dual-rumble vibration motor testing.
- Dual X/Y analog radar oscilloscope with live resting offset %
- 360° stick circularity error test & deadzone calculator
- Continuous analog trigger depth gauges (LT/RT / L2/R2)
- Dual-rumble haptic actuator test & 1-click Markdown export
Display & Monitor Calibration Suite
All-in-one screen calibration suite. Features fullscreen dead/stuck pixel inspection, 60Hz-360Hz motion blur and overdrive ghosting analyzer, 256-step 10-bit color banding test, and shadow clipping verification.
- Native fullscreen dead pixel inspection (8 solid color targets)
- Motion ghosting & overdrive overshoot analyzer (60Hz to 360Hz)
- 256-step 8-bit vs. 10-bit color banding & shadow clipping
- High-frequency stuck pixel revival flasher & markdown report
WebGPU & WebGL GPU Stress Test
Push your graphics card to 100% in your browser. Runs heavy raymarching fractal shaders to measure sustained average FPS, 1% low pacing, thermal throttling decay curves, and unmasked GPU model.
- Real-time raymarching shader with multi-light volumetric load
- Sustained average FPS, 1% low, and 0.1% low micro-stutter pacing
- Real-time thermal throttling & power decay curve timeline
- Unmasked GPU renderer identification & markdown benchmark export
Content Security Policy (CSP) Generator & Validator
Interactive Content Security Policy builder and XSS vulnerability auditor. Configure strict baseline directives, test against unsafe-inline flaws, and export ready-to-deploy configs for Nginx, Apache, and Next.js.
- Live CSP compiler with strict baseline security presets
- Automated XSS and clickjacking vulnerability audit engine
- Nonces and strict-dynamic CSP Level 3 policy support
- 1-click export for Nginx, Apache, Caddy & Next.js middleware
Offline JWT Debugger & Security Auditor
Decode and audit JSON Web Tokens locally in browser memory with zero server transmission. Automatically flags algorithm 'none' (CVE-2015-9235), expired tokens, weak HMAC secrets, and missing claims.
- 100% In-browser parsing with air-gapped security badge
- Color-coded header, payload, and signature breakdown
- Automated CVE-2015-9235 alg:none & expiration audit
- Local Web Crypto API HMAC signature verification
CORS Misconfiguration Evaluator
Simulate cross-origin preflight requests (OPTIONS) and audit API response headers. Identifies dangerous wildcard origin credentials, unvalidated origin reflections, and trusted null origin data leaks.
- Interactive preflight OPTIONS simulator & origin tester
- Flags wildcard (*) origin paired with credentials: true
- Detects dynamic origin reflection & trusted null origins
- Production-hardened CORS templates for Nginx & Express
Password Entropy & Crack-Time Calculator
Evaluate password resistance using Claude Shannon's mathematical information entropy formula (E = L × log2 R). Estimate brute-force crack times against 8x RTX 4090 GPU clusters across NTLM, Bcrypt, and Argon2id.
- Shannon Information Entropy calculation (bits of entropy)
- Brute-force crack time estimates for 8x RTX 4090 GPU rigs
- Deductions for common dictionary words & keyboard walks
- Cryptographically secure client-side password generator
Cryptographic Hash & File Checksum Hasher
Compute cryptographic hashes and verify software file checksums in real time. Generates SHA-256, SHA-512, SHA-384, SHA-1, MD5, CRC32, and HMAC-SHA256 with 100% in-browser air-gapped zero upload security.
- Instant dual text and drag-and-drop file hashing
- SHA-256, SHA-512, MD5, CRC32 & HMAC-SHA256 support
- Live expected checksum comparator & match badge
- 100% local Web Crypto API execution with zero telemetry
IPv6 Address Expander & Compressor
Normalize IPv6 addresses to canonical RFC 5952 zero-suppression notation, expand to 8 full 16-bit hextets, and generate RFC 3596 reverse DNS ip6.arpa PTR records.
- Canonical RFC 5952 zero-compression algorithm
- Full 32-character hexadecimal 8-hextet expansion
- Reverse DNS PTR record generator (ip6.arpa)
- 128-bit binary and BigInt decimal representation
IPv6 Subnet & Prefix Slicing Calculator
Slice enterprise /48 and broadband /56 allocations into customer /64 subnets. Computes borrowed bits, SLAAC host capacity, allocation badges, and paginated subnet slices.
- 128-bit precision math powered by JavaScript BigInt
- Architectural tags (/32 RIR, /48 Enterprise, /56 SOHO, /64 SLAAC)
- Paginated subnet slices with network start and last addresses
- 1-click Markdown export of IP allocation plans
IPv4 to IPv6 Transition & Embedding Tool
Map legacy IPv4 addresses into standard dual-stack IPv6 formats. Generates IPv4-Mapped (::ffff:), NAT64 well-known (64:ff9b::/96), 6to4 tunneling (2002::/16), and ISATAP formats.
- IPv4-Mapped IPv6 (RFC 4291) for dual-stack socket listeners
- NAT64 Well-Known Prefix (64:ff9b::/96, RFC 6052)
- 6to4 automated tunneling prefix generator (RFC 3056)
- 32-bit hex and binary decomposition table
IPv6 Special Address & Scope Classifier
Classify IPv6 address scopes (GUA, ULA, Link-Local), inspect routability boundaries, decode multicast flags & scope headers, and detect SLAAC EUI-64 hardware MAC address leaks.
- Architectural scope audit (Global vs Link-Local vs Private ULA)
- Routability boundary check across public Internet and Layer 2 links
- Multicast RFC 4291 header flag & scope decoding
- Hardware MAC address privacy leak detection from EUI-64 interface IDs
MX Record & Mail Host Priority Lookup
Verify mail host routing preferences, inspect DNS TTL, and resolve server IP addresses in real time via DNS-over-HTTPS. Detects single points of failure and priority conflicts.
- Real-time Cloudflare & Google DNS-over-HTTPS query engine
- Sorts MTAs by RFC 5321 numerical priority preferences
- Parallel forward A/AAAA IP resolution for all mail hosts
- 1-click export of authoritative MX audit reports
Reverse DNS (rDNS) & FCrDNS Checker
Check Forward-Confirmed reverse DNS (FCrDNS) to verify that sending mail server IPs match their hostnames bidirectionally. Prevents Gmail and Outlook spam rejections.
- Bidirectional FCrDNS forward confirmation audit
- IPv4 in-addr.arpa and IPv6 ip6.arpa pointer resolution
- Flags PTR mismatches that cause 550 5.7.1 spam rejections
- Zero server logging with direct browser DoH queries
SPF Record Syntax & Lookup Counter
Audit SPF syntax, count recursive DNS lookups against the strict RFC 7208 10-mechanism limit with visual progress gauge, and flag catastrophic +all spoofing loopholes.
- Visual RFC 7208 10-lookup mechanism counter gauge
- Flags multiple SPF records that trigger PermError
- Differentiates free IP mechanisms from costly DNS lookups
- Detects insecure +all qualifiers and evaluates -all vs ~all
DMARC Record Generator & Policy Tester
Build production-hardened v=DMARC1 records with p=reject enforcement, configure aggregate RUA reporting, and test live published domain records via DoH in real time.
- Interactive DMARC policy builder (none, quarantine, reject)
- Configures aggregate RUA and forensic RUF reporting tags
- Fine-tunes relaxed vs strict SPF & DKIM alignment modes
- Live DNS tester verifying published _dmarc.domain TXT records
DKIM Key & Selector Inspector
Query published DKIM public keys at [selector]._domainkey, audit RSA key bit strength (1024-bit vs 2048-bit), and check revocation status in real time.
- Authoritative [selector]._domainkey.[domain] TXT lookup
- Estimates RSA key bit length (flags weak 1024-bit keys)
- Detects empty p= revocation tags and test mode flags
- 1-click copy of raw public key cryptographic strings
SMTP Port & Security Checker
Compare email transmission ports (25, 465, 587, 2525), diagnose residential ISP and cloud firewall blocks, test STARTTLS vs. Implicit TLS, and troubleshoot SMTP response codes.
- Interactive architecture matrix for ports 25, 465, 587, 2525
- Explains RFC 8314 shift to Implicit TLS over opportunistic STARTTLS
- CLI OpenSSL commands for manual port diagnostics
- Comprehensive cheat sheet for SMTP 2xx, 4xx, and 5xx error codes
Inbound Open Port & Firewall Checker
Test whether your local router, VPS, or cloud server exposes open ports to the public internet. Initiates non-blocking external TCP probes for web, mail, SSH, and database ports with Open, Closed, and Filtered diagnostics.
- Automatic public IPv4/IPv6 client IP detection
- Presets for Mail (25, 465, 587), Web/SSH (80, 443, 22), & DBs (3306, 5432)
- Stateful firewall packet drop (Filtered) vs. host reset (Closed) detection
- Real-time TCP handshake latency & 1-click Markdown export
Linux Firewall Rule Generator
100% client-side Linux firewall syntax builder. Instantly compile clean, syntax-perfect rules for UFW, iptables, nftables, pf, and firewalld with CIDR restrictions, interface binding, and brute-force rate-limiting.
- Instant copy tabs for UFW, iptables, nftables, pf & firewalld
- Presets for SSH, Web, Mail, MySQL, Postgres, Redis, and WireGuard
- Source IP and CIDR subnet whitelist filtering
- Management cheat sheet with reload, list, and delete commands
Cloudflare WAF Expression Builder
Translate security policies into Cloudflare Firewall Rule expressions. Defend sensitive APIs, challenge automated datacenter scrapers by ASN, enforce Turnstile challenges on high threat scores, and exempt AdSense /ads.txt.
- Wireshark-syntax expression generator ready for Cloudflare Dashboard
- Block common scraper ASNs (AWS, DigitalOcean, OVH, Hetzner)
- Exempt /ads.txt, robots.txt, and payment webhooks to protect revenue
- Export directly to Terraform HCL and Cloudflare REST API JSON
Engineered for Speed, Privacy & Core Web Vitals
BestUtilities adheres to modern web engineering principles to deliver maximum utility without user tracking, layout shifts, or bloated JavaScript bundles.
Zero Cumulative Layout Shift
All ad slots and dynamic content modules use hard-coded min-height specifications. Pages render instantly without annoying jumping or accidental clicks.
Automatic Storage Ephemerality
Temporary mailboxes and message buffers are automatically cleared by background cron workers. We maintain no persistent customer profiles or relational backups.
1-Hour Cached Interbank Feeds
Foreign exchange calculations rely on static 1-hour cached snapshots of live interbank markets, providing consistent calculations with sub-millisecond edge response times.
Reserved banner container configured with strict Core Web Vitals CLS = 0 layout preservation.