AS—
—
—
ASN Lookup
Every network on the internet has an AS number — an Autonomous System Number, the identifier for a block of addresses under one routing policy. Enter one to see who holds it, which registry issued it, exactly what it's announcing right now, and which networks it connects to. No AS number to hand? Paste a domain or an IP and we'll find the AS behind it first.
Try:
Enter an AS number above — or paste a domain or an IP address and we'll find which AS announces it.
IPv4 Prefixes
—
—
IPv6 Prefixes
—
announced blocks
Upstream Networks
—
seen above it in BGP paths
Downstream Networks
—
seen below it in BGP paths
🏛️ Registration
AS Number
—
Holder
—
Registry
—
Issued From Block
—
Block Name
—
Currently Announcing
—
Unique Neighbours
—
Checked At
—
🔗 BGP Neighbours
Networks observed directly adjacent to this AS in real BGP paths. Direction is what route collectors saw — it is not proof of a commercial provider/customer relationship, and RIPEstat labels some adjacencies "uncertain" for exactly that reason.
📡 Announced Prefixes
📡 This is live routing data. Prefixes and neighbours come from RIPEstat, which aggregates what BGP route collectors around the world are actually seeing right now — not a static registry dump. An AS that has just changed what it announces will reflect that here within hours.
HOW IT WORKS
What An AS Number Actually Is
The internet isn't one network — it's roughly a hundred thousand independent ones that agree to carry each other's traffic. Each gets an Autonomous System Number from a regional registry, and uses BGP to announce "these IP ranges are reachable through me". This page combines three free RIPEstat data calls: as-overview for who holds the number and which IANA block it came from, announced-prefixes for exactly what it's routing at this moment, and asn-neighbours for the networks seen adjacent to it in real observed paths. If one call is slow or unavailable, only that section is left blank — the rest is still shown rather than failing the whole lookup.
What else can you check?
These tools all work on the same connection and address data — pick whichever question you actually have.
Want to see the full path to a site?
DNS, redirects, every hop, the CDN, TLS and the origin server.
Want to know your public IP?
See your IPv4 and IPv6 addresses, location, ISP and ASN.
Want to check your tower & route?
Live ping, speed, DNS, traceroute and a map of nearby points.
Want to ping from around the world?
Real latency from real probes across 12 countries, live on a map.
Want to locate any IP address?
City, region, country and coordinates for any public IP.
Want to know if an IP is risky?
Proxy, VPN, Tor, hosting and abuse-report indicators.
Want to know if you're blacklisted?
Check an address against major spam and abuse DNSBLs.
Want to know who owns an IP?
Network owner, ASN, CIDR range and abuse contact.
Want to test your connection speed?
Measure real download, upload, ping and jitter.
Want to see what changed?
Word-level diff between two blocks of text or code.
Want to know if a DNS change is live yet?
Compare answers from five independent public resolvers.
Want to verify a domain's nameservers?
Direct authoritative checks, glue records and SOA serials.
Want to check a domain's DNSSEC setup?
DNSKEY, DS records, signature expiry and real validation.
Want to see the hop-by-hop path to a server?
A real traceroute from a genuine probe anywhere in the world.
Want to know if a server port is open?
A real TCP connection attempt - open, closed or filtered.
Want to measure latency to a server?
Real connect timing - min/avg/max, jitter and connection loss.
Want a clean URL slug from a title?
Real transliteration, stop words and batch mode.
Want to find and replace across a document?
Regex, capture groups and a live preview before you commit.
Want to find the invisible character?
Code points, escapes, bytes and hidden-character detection.
Want to escape text for HTML?
Minimal, named or numeric entities, attribute-safe.
Want to strip emoji cleanly?
Whole clusters - no half-flags or stray modifiers left.
Want to spot repeated words?
Frequency, density and accidental doubles like "the the".
Want to know if a URL is cached?
Two requests prove whether your CDN is really caching it.
Want to see what a site knows about you?
Storage, cookies, tokens and what your browser actually cached.
Want to run that check on any site?
One-click bookmarklet reads storage and tokens where they live.
Want to know who your site talks to?
Renders the page and names every outside company it contacts.
Is your site one address or four?
www, non-www, http and https - which serve, which redirect.
Need to build an Authorization header?
Basic, Bearer, API key, Digest and AWS SigV4 - signed in your browser.
Want to tidy up a messy SQL query?
Beautify, minify, lint and convert keyword casing for six dialects.
Need to work out a percentage?
Nine calculators covering every way a percentage gets asked.
Want to work out a rise or a raise?
Increases, growth, compounding and CAGR, with the working shown.
Want to work out a discount or a drop?
Discounts, stacked sales and depreciation, with the working shown.
What is actually on that page?
Words, reading time, readability, every image, embed and link.
Need a favicon that works everywhere?
Every size, a real multi-resolution .ico, and the tags to paste.
What headers does a site send back?
Every response header on every redirect hop, explained.
Need to test a regular expression?
Live matches, capture groups, replace preview and code snippets.
Need a JPG as a PNG?
Batch convert in your browser, with optional transparent background.
Need somewhere to jot things down?
Private notes, links, to-dos and reminders saved in your browser.
Need just some pages of a PDF?
Split by page, range or chunk, or extract the pages you pick.
What is hiding inside that image?
EXIF camera settings, GPS tags, colour palette and web checks.
ASN Lookup FAQ
What's the difference between this and the ASN & IP Owner Lookup?
That tool starts from an IP address and answers "who owns this address, and who do I report abuse to?". This one starts from the AS number and describes the network itself — everything it announces and who it connects to. You can paste an IP here too and we'll resolve it to its AS first.
Why does the holder name look like a code, e.g. "GOOGLE - Google LLC"?
That's the registry's own record: a short handle followed by the legal organisation name. We show it verbatim rather than tidying it, so it matches what you'd find querying the registry directly.
What does "uncertain" mean for a neighbour?
Route collectors saw the two networks adjacent in a BGP path but couldn't consistently determine which side was upstream. Rather than guess a direction, RIPEstat marks it uncertain and so do we.
Why are only some prefixes listed?
Large transit networks announce thousands of prefixes — more than is useful to render in a browser. The full counts are always shown accurately, and the list is capped at 250 per address family with a note when it's been truncated.
Can an AS be registered but not announcing anything?
Yes, and it's common. A number may be reserved for future use, kept for a network that's since been absorbed, or temporarily withdrawn. The "Currently Announcing" field reports exactly that state.
