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IP Address Lookup
Detect your public IPv4/IPv6 address, browser info, connection type, screen resolution, timezone, and device details. Copy any info with one click.
2 worked examples
Methodology and sources included
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Reviewed April 27, 2026
Security
IP Address Lookup is a free, browser-based security tool. Detect your public IPv4/IPv6 address, browser info, connection type, screen resolution, timezone, and device details. Copy any info with one click.
What this tool does
- IPv4 and IPv6 detection via ipify API
- browser and OS detection
- connection type and speed info
- screen resolution and pixel ratio
- timezone and locale details
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An IP address lookup resolves a raw IPv4 or IPv6 address into the metadata that actually tells you what it is: which autonomous system (ASN) announces it, which country and city it geolocates to, whether it belongs to a known cloud provider, VPN, Tor exit, or residential ISP, and what its reverse DNS (PTR) record points at. FastTool's lookup tool uses the same public data sources — RIR WHOIS (ARIN, RIPE, APNIC, LACNIC, AFRINIC), MaxMind GeoLite, and the Team Cymru IP-to-ASN service — that security teams rely on every day, and presents them in one digestible panel so you do not have to open five tabs to answer a single question about an IP in your logs.
Why This Matters
Abuse triage, fraud detection, rate-limit tuning, geo-compliance audits, and incident response all start with who is this IP?. Getting a definitive answer quickly — including whether the address is a datacenter range (likely a scraper or bot) or a residential CGNAT pool (likely a real user) — changes how you respond. A two-minute lookup can be the difference between blocking an attacker and blocking ten thousand legitimate customers behind the same mobile carrier NAT gateway.
Real-World Case Studies
- Credential-stuffing triage. A security analyst sees a thousand failed logins from
45.134.26.x. The lookup returns ASN 204601, a known bulletproof hosting provider in eastern Europe, with no residential traffic on that prefix. She adds the/24to the WAF block list with high confidence and no risk of a false positive against real customers. - Support ticket verification. A customer claims they cannot reach the site from
Singapore. The support engineer looks up the IP from the user's email headers, sees it geolocates toSão Paulo, BRon a Vivo residential prefix, and gently asks whether the user is travelling — avoiding an unnecessary network escalation. - CDN origin leak audit. A DevOps engineer checks whether
origin.example.comis still exposing its real IP despite Cloudflare proxying. The lookup reveals ASN 13335 (Cloudflare) — good. Two weeks later, a follow-up check on a new subdomain shows ASN 16509 (AWS) leaking the origin EC2 address, and she patches the DNS record before attackers can bypass the WAF.
Technical Deep Dive
IP geolocation is not an exact science. The RIR databases are authoritative for ownership and ASN, but city-level precision depends on commercial datasets that infer location from latency, routing, and user-submitted corrections; accuracy ranges from ~80% at the country level (per MaxMind's published metrics) down to roughly 50-60% at city level depending on the region. Reverse DNS (in-addr.arpa for IPv4, ip6.arpa for IPv6) is controlled by whoever runs the address block and can say anything, so PTR records are a hint and never proof of ownership. The lookup cross-references multiple sources and flags disagreement so you can weigh the evidence instead of trusting a single number.
💡 Expert Pro Tip
Always check the ASN and the reverse DNS and the geolocation. If all three agree (e.g. ASN 15169, PTR google-public-dns-a.google.com, geo Mountain View), the answer is solid. If they disagree — residential ASN with a datacenter PTR, or vice versa — treat the IP as suspicious until you know why the signals conflict.
Methodology, Sources & Accessibility
Methodology
Methodology: trust the browser's crypto, minimise attack surface, favour standards over cleverness. The tool does not roll its own cryptography. Every parameter defaults to current best-practice (NIST-approved curves, SHA-256 or better hashes, authenticated encryption modes, secure random generation). Secrets pasted by the user are treated as opaque bytes and cleared from memory to the extent JavaScript allows.
Authoritative Sources
- NIST Cryptographic Standards — The US reference for cryptographic algorithm selection and parameters.
- OWASP — Open Web Application Security Project — Community reference for web application security practices.
- IETF Security RFCs — Internet Engineering Task Force working groups on protocol security.
- W3C Web Cryptography API — The browser-native cryptography specification this tool uses.
- W3C Web Standards — The World Wide Web Consortium publishes HTML, CSS, DOM, and accessibility specifications that browser-based tools rely on.
About This Tool
IP Address Lookup is a free, browser-based utility in the Security category. Detect your public IPv4/IPv6 address, browser info, connection type, screen resolution, timezone, and device details. Copy any info with one click. Standard processing runs on the client — no account is required, and there is no paywall or usage cap. The implementation uses audited standard-library primitives and published specifications rather than proprietary algorithms, so the output is reproducible and transparent.
Accessibility
FastTool targets WCAG 2.2 Level AA conformance: keyboard-navigable controls, visible focus states, semantic HTML, sufficient colour contrast, and screen-reader compatibility. If you encounter an accessibility issue, please reach us via the site footer.
Stop switching between apps — IP Address Lookup lets you detect your public IPv4/IPv6 address, browser info, connection type, screen resolution, timezone, and device details. Copy any info with one click directly in your browser. The 2024 NIST post-quantum cryptography finalization (ML-KEM, ML-DSA) pushed hybrid-PQC deployments into the mainstream, and IP Address Lookup uses browser-based processing for standard inputs to reduce unnecessary exposure to remote services. Standard input stays on your device — IP Address Lookup uses client-side JavaScript for core processing, keeping the workflow private without requiring an account. The typical workflow takes under a minute: open the page, enter your input or configure security settings, review the output, and copy or download the secure output. There is no learning curve and no configuration required for standard use cases. With features like IPv4 and IPv6 detection via ipify API and browser and OS detection, plus connection type and speed info, IP Address Lookup covers the full workflow from input to output. The layout is designed for speed: enter your input or configure security settings, hit the action button, and copy or download the secure output — all in a matter of seconds. Add IP Address Lookup to your bookmarks for instant access anytime the need arises.
You might also like our IP Subnet Calculator. Check out our User Agent Parser. For related tasks, try our Secure Password Generator.
What Makes IP Address Lookup Useful
- IPv4 and IPv6 detection via ipify API — reducing manual effort and helping you focus on what matters
- browser and OS detection to handle your specific needs efficiently
- connection type and speed info included out of the box, ready to use with no extra configuration
- Full screen resolution and pixel ratio support so you can work without switching to another tool
- timezone and locale details for faster, more precise results
- copy IP or all info to clipboard included out of the box, ready to use with no extra configuration
- refresh button for re-detection included out of the box, ready to use with no extra configuration
- online/offline status monitoring — a purpose-built capability for security professionals
- full user agent string display that saves you time by automating a common step in the process
- device memory and hardware concurrency that saves you time by automating a common step in the process
- Built-in examples that demonstrate how the tool works with real data
- faster input handling — reducing manual effort and helping you focus on what matters
- Dedicated clear error messages functionality designed specifically for security use cases
- Completely free to use with no registration, no account, and no usage limits
- Runs in your browser for standard workflows, with no account or upload queue required
- Responsive design that works on desktops, tablets, and mobile phones
Benefits of IP Address Lookup
- Reliable and always available — because IP Address Lookup runs entirely in your browser with no server dependency, it works even when your internet connection is unstable. After the initial page load, you can disconnect completely and the tool continues to function without interruption.
- Speed that saves real time — IP Address Lookup is designed to help you enhance your online security as quickly as possible. The streamlined interface eliminates unnecessary steps, and instant local processing means you get your result in seconds rather than minutes.
- Privacy you can verify — unlike tools that merely promise privacy, IP Address Lookup uses a client-side architecture that you can independently verify. Open your browser's Network tab and confirm: standard tool inputs are not intentionally sent to a FastTool application server during processing.
- Professional-quality output — IP Address Lookup delivers results, including IPv4 and IPv6 detection via ipify API, browser and OS detection that meet professional standards. The output is clean, properly formatted, and ready to use in your projects, reports, or communications without additional cleanup.
Complete Guide to Using IP Address Lookup
- Navigate to the IP Address Lookup page. The tool is ready the moment the page loads.
- Enter your data using the input field provided. You can enter your input or configure security settings manually or paste from your clipboard. Try IPv4 and IPv6 detection via ipify API if you want a quick start. IP Address Lookup accepts a variety of input formats.
- Adjust settings as needed. IP Address Lookup offers browser and OS detection and connection type and speed info so you can tailor the output to your exact requirements.
- Press the action button and your result appears immediately. All computation happens in your browser, so there is zero latency.
- Review your result carefully. IP Address Lookup displays the output clearly so you can verify it meets your expectations before using it elsewhere.
- Save your output — click the copy button to place it on your clipboard, ready to paste into your target application, document, or communication.
- Come back anytime to use IP Address Lookup again. Bookmark this page for quick access, and remember that every feature remains free and unlimited on every visit.
Tips from Power Users
- Test edge cases: very short inputs, very long inputs, special characters, and Unicode. Security tools need to handle all inputs correctly, and testing here helps you trust IP Address Lookup.
- Keep your browser up to date. Client-side security tools rely on your browser's JavaScript engine and crypto APIs, which receive regular security patches.
- Remember that client-side processing means your network administrator cannot see your data, but browser extensions can. Disable unnecessary extensions when handling sensitive input.
Avoid These Mistakes
- Pasting real credentials into security tools to 'test' them. Even client-side tools live in a shared browser process alongside extensions — use throwaway test values for all experimentation.
- Skipping 2FA after improving your password. A strong password without a second factor is only half a defense — SMS, TOTP, or WebAuthn closes the authentication loop.
- Reusing a generated password across multiple sites. Every site should get its own unique secret — IP Address Lookup can produce hundreds instantly, so there is no excuse to reuse.
- Trusting any single hash or token in isolation. For authentication systems, always layer hashing with salting, key-stretching (bcrypt/scrypt/argon2), and rate-limiting — a single primitive is never enough.
- Mistaking encoding (Base64, URL-encode, hex) for encryption. Encoding is reversible and offers zero confidentiality — always pair with a proper cipher when secrecy actually matters.
See IP Address Lookup in Action
Looking up a public IP
Input
8.8.8.8
→
Output
Location: Mountain View, CA, US
ISP: Google LLC
Timezone: America/Los_Angeles
IP geolocation maps an IP address to an approximate physical location using databases maintained by regional registries.
Looking up a private IP
Input
192.168.1.1
→
Output
Private IP address — no geolocation available.
Range: 192.168.0.0/16 (RFC 1918)
Private IP ranges (10.x, 172.16-31.x, 192.168.x) are not routable on the internet and cannot be geolocated.
Why Choose IP Address Lookup
| Feature | Browser-Based (FastTool) | Desktop Software | Cloud-Based Service |
|---|---|---|---|
| Price | Free forever | Varies widely | Monthly subscription |
| Data Security | Client-side only | Depends on implementation | Third-party data handling |
| Accessibility | Open any browser | Install per device | Create account first |
| Maintenance | Zero maintenance | Updates and patches | Vendor-managed |
| Performance | Local device speed | Native performance | Server + network dependent |
| Learning Curve | Minimal, use immediately | Moderate to steep | Varies by platform |
When a Different Tool Is Better
No tool is perfect for every scenario. Here are situations where a different approach will serve you better:
- When conducting a professional security audit. Penetration testing, threat modeling, and formal review need dedicated platforms (Burp Suite, Metasploit, commercial SAST/DAST) — not a single-purpose web tool.
- When protecting critical production credentials. IP Address Lookup is safe for exploration and testing, but real secrets belong in a password manager (1Password, Bitwarden) or secrets vault — never in browser history.
- When implementing security for a regulated industry. Healthcare, finance, and government workloads have compliance-certified tooling requirements that general-purpose browser tools do not meet.
How IP Geolocation Works
Every device connected to the internet has an IP (Internet Protocol) address — a numerical label that serves two functions: network interface identification and location addressing. IPv4 addresses use 32 bits expressed as four decimal octets (e.g., 192.168.1.1), providing approximately 4.3 billion unique addresses. This pool was exhausted in 2011 for regional registries, driving the adoption of IPv6, which uses 128 bits (expressed as eight groups of hexadecimal digits like 2001:0db8:85a3::8a2e:0370:7334) — providing 340 undecillion addresses, enough for every grain of sand on Earth to have billions of addresses.
IP geolocation determines the approximate physical location of an IP address by cross-referencing regional internet registry (RIR) databases that record which IP blocks are allocated to which organizations and geographic regions. Accuracy varies: country-level identification is typically 95-99% accurate, city-level is 50-80% accurate, and precise street-level location is generally not possible from IP alone (despite what crime shows suggest). VPNs, corporate networks, and mobile carriers can make geolocation unreliable — a user on a VPN in Tokyo might show a US-based IP, and a mobile user might show an IP registered to their carrier's headquarters hundreds of miles away.
How It Works
IP Address Lookup uses the Web Crypto API — the same cryptographic primitives that secure HTTPS connections and online banking with capabilities including IPv4 and IPv6 detection via ipify API, browser and OS detection, connection type and speed info. Random number generation uses crypto.getRandomValues(), providing cryptographically secure randomness. Hashing operations implement the full algorithm specification (SHA-256, SHA-512, etc.) natively in the browser. Standard security operations run client-side, reducing unnecessary network handling.
Interesting Facts
The average cost of a data breach in 2024 was $4.88 million globally, making security tools a genuine cost-saving investment.
NIST finalized post-quantum cryptography standards (ML-KEM, ML-DSA, SLH-DSA) in 2024, and major browsers plus cloud providers began hybrid deployments through 2025-2026 to defend against future quantum attacks on captured TLS traffic.
Concepts to Know
- Salt (Cryptography)
- Random data added to a password before hashing. Salting prevents attackers from using precomputed hash tables (rainbow tables) to crack passwords.
- Brute Force Attack
- An attack method that systematically tries every possible combination until the correct one is found. Strong passwords and rate limiting are the primary defenses against brute force.
- HMAC (Hash-based Message Authentication Code)
- A specific construction for calculating a message authentication code using a hash function combined with a secret key. HMACs verify both data integrity and authenticity.
- AES (Advanced Encryption Standard)
- A symmetric encryption algorithm adopted by the US government and widely used worldwide. AES operates on 128-bit blocks with key sizes of 128, 192, or 256 bits.
Questions and Answers
What is my IP address?
My IP address is central to what IP Address Lookup does. Detect your public IPv4/IPv6 address, browser info, connection type, screen resolution, timezone, and device details. Copy any info with one click. With IP Address Lookup on FastTool, you can work with my IP address using IPv4 and IPv6 detection via ipify API, browser and OS detection, connection type and speed info, all running client-side in your browser. No account creation or software installation needed — results appear instantly.
What is the difference between IPv4 and IPv6?
Difference between IPv4 and IPv6 is central to what IP Address Lookup does. Detect your public IPv4/IPv6 address, browser info, connection type, screen resolution, timezone, and device details. Copy any info with one click. With IP Address Lookup on FastTool, you can work with difference between IPv4 and IPv6 using IPv4 and IPv6 detection via ipify API, browser and OS detection, connection type and speed info, all running client-side in your browser. No account creation or software installation needed — results appear instantly.
Check out: IP Subnet Calculator
Can websites see my IP address?
As a browser-based security tool, IP Address Lookup addresses this by letting you enter your input or configure security settings and get results instantly. Detect your public IPv4/IPv6 address, browser info, connection type, screen resolution, timezone, and device details. Copy any info with one click. It is free, private, and works on any device with a modern web browser. Tool input is handled locally where browser APIs support it, and FastTool does not require uploads for standard use.
How do I find my public IP address?
IP Address Lookup makes it easy to find my public IP address. Open the tool, enter your input or configure security settings, configure options such as IPv4 and IPv6 detection via ipify API, browser and OS detection, connection type and speed info, and get your result immediately. Everything is processed client-side in your browser for maximum speed and privacy.
You might also find useful: User Agent Parser
Is my IP address secure?
Your privacy is built into how IP Address Lookup works. Core computation happens in your browser via client-side JavaScript. Tool input is not intentionally logged or stored remotely by FastTool. You can confirm this yourself by checking the Network tab in your browser developer tools.
What is IP Address Lookup?
IP Address Lookup is a free, browser-based security tool available on FastTool. Detect your public IPv4/IPv6 address, browser info, connection type, screen resolution, timezone, and device details. Copy any info with one click. It includes IPv4 and IPv6 detection via ipify API, browser and OS detection, connection type and speed info to help you accomplish your task quickly. No sign-up or installation required — it runs entirely in your browser with instant results. Standard processing happens client-side, so tool input does not need a FastTool application server.
Check out: Email Validator
How to use IP Address Lookup online?
To get started with IP Address Lookup, simply open the tool and enter your input or configure security settings. The interface guides you through each step with clear labels and defaults. After processing, you can copy or download the secure output. No registration or downloads required — everything is handled client-side.
Is my data safe when I use IP Address Lookup?
IP Address Lookup keeps standard tool input local. There are no account workflows or FastTool databases attached to the tool output, and ads or analytics are limited to standard page telemetry rather than tool-input storage. This approach is fundamentally different from cloud-based tools that require uploading your input to remote servers for processing.
You might also find useful: HTTP Security Headers Generator
Can I use IP Address Lookup on my phone or tablet?
Yes, IP Address Lookup works perfectly on mobile devices. The responsive design ensures buttons and inputs are sized for touch interaction, with adequate spacing to prevent accidental taps. Whether you are on a small phone screen or a large tablet, the experience remains smooth, complete, and fully functional. Performance is optimized for mobile browsers, so even on older devices you will get fast results without lag or freezing.
Does IP Address Lookup work offline?
Once the page finishes loading, IP Address Lookup works without an internet connection. All computation runs locally in your browser using JavaScript, so there are no server requests during normal operation. Feel free to disconnect after the initial load — your workflow will not be affected. Bookmark the page so you can reach it quickly the next time you are online, and the tool will be ready to use again as soon as the page loads.
Check out: URL Parser
Why choose IP Address Lookup over other security tools?
Three things set IP Address Lookup apart: it is free with no limits, it keeps standard processing in the browser, and it works on any device without installation. Most competing tools require accounts, charge for advanced features, or require project uploads for processing. IP Address Lookup avoids all three of these issues by running everything client-side. Additionally, the interface is available in 21 languages and works offline after the initial page load, which most alternatives do not offer.
Practical Scenarios
Development Security
Integrate IP Address Lookup into your development workflow to handle security-related tasks like token generation, encoding, or hash verification. The instant results and copy-to-clipboard functionality make this workflow fast and efficient, letting you move from task to finished output in a matter of seconds.
Compliance Checks
Verify that your security configurations meet best practices using IP Address Lookup as a quick validation tool. The browser-based approach means you can start immediately without any installation, making it practical for time-sensitive situations where setting up dedicated software is not an option.
Personal Privacy
Protect your personal information by using IP Address Lookup to generate or process security-related data entirely in your browser. This is a scenario where having a reliable, always-available tool in your browser saves meaningful time compared to launching a desktop application or searching for an alternative.
Penetration Testing Prep
Security testers can use IP Address Lookup to prepare test data, encode payloads, or generate tokens during assessments. The browser-based approach means you can start immediately without any installation, making it practical for time-sensitive situations where setting up dedicated software is not an option.
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References & Further Reading
Authoritative sources and official specifications that back the information on this page.
- RFC 791 - Internet Protocol — IETF / RFC Editor
Authoritative IPv4 spec
- RFC 8200 - Internet Protocol, Version 6 (IPv6) Specification — IETF / RFC Editor
IPv6 specification
- IANA IPv4 Address Space Registry — IANA
Authoritative allocation registry
- IP address - Wikipedia — Wikipedia
Background