While working on the ASmap dashboard I collected a list of crawlers and DNS seeders. Ended up checking quite a few of them, so in case it helps someone, here is the list:
Crawlers / node datasets
(Every DNS seeder runs its own network crawler internally - some operators publish that crawler’s full view as a dump, which is why I put several of the seeders from the section below also in here)
Full dnsseed.dump of achow101’s crawler: one line per known node with uptime stats (2h to 30d), block height, services, user agent. A makeseeds.py source with the widest service-bit coverage.
BitMEX Research node explorer: one cumulative “last seen” CSV per day with IP, country, ISP, services, user agent, height. Daily since 2026-06-26, weekly before. The site credits ayeowch/bitnodes as its network crawler.
seed.bitcoin.fish.foo is a ninth, non-Core seeder run by willcl-ark that also answers (its dump is in the table above)
seed.bitcoin.haf.ovh is a tenth, non-Core seeder run by retropex that also answers and publishes a full dump (in the table above)
Two former Core seeds are still live and answering: dnsseed.bitcoin.dashjr-list-of-p2p-nodes.us (removed from vSeeds in Dec 2025, still in Knots’ chainparams.cpp) and seed.bitcoinstats.com (removed in Aug 2024)
octavio.xyz monitors the quality of some of these seeds daily (advertised, reachable, stale, pristine, duplicate) via a small JSON API, own measurements since 2026-05-17. It also hosts virtu’s older series (Oct 2022 to Nov 2025, originally at 21.ninja/dns-seeds) as static CSVs under demo-data/
Related, but no raw node data
the dnsseedrs dashboard is willcl-ark’s frontend for his fish.foo dump above
Two weeks ago I posted the list of live seeders and crawler datasets above. Since then I have been archiving all of them daily in bitcoin-seeder-data: DNS answers from the eight Core seeds plus fish.foo every 6 hours, and every published dump once a day. Here is what the first two weeks show.
All population and overlap numbers below are clearnet only (IPv4 + IPv6). Onion, I2P and CJDNS are left out of those comparisons.
Clearnet population sizes
Raw totals are not comparable across sites, each operator uses a different reachability rule:
source
clearnet
reachability rule
KIT dossier
9,669
all entries in the public dossier
bitnod.es
9,319
last seen within 1 day of the newest export
btcnodes
8,793
completed handshake in one crawl round
sipa seeds.txt (frozen since 2025-11)
8,947
seeder good flag
fish.foo seeds.txt
5,899
seeder good flag
achow101 seeds.txt
4,250
seeder good flag
With the address family fixed, KIT / bitnod.es / btcnodes sit near 9k. The seeder good sets are smaller: they require uptime scores over windows from 2h to 30d, not only a recent sighting.
KIT’s dossier accumulates over months. Cutting on “lastConnect” changes the count: 3,271 within 1d, 5,129 within 7d, 9,669 for all entries.
bitnod.es moves day to day inside the 9k band (export timing and uneven daily buckets I think). A 7-day rolling mean removes most of that movement, but the level sits a few hundred hosts above btcnodes, consistent with the wider 1-day last-seen window.
Pairwise overlap
bitnod.es vs btcnodes (both forks from ayeowch/bitnodes). On 2026-07-21 the two agree on 8,166 clearnet hosts: 88% of the bitnod.es set (9,319) and 93% of the btcnodes set (8,793). Of the 1,153 bitnod.es-only hosts that day, 783 (68%) appear in at least one archived btcnodes snapshot from the previous week; 370 (32%) do not. Part of the gap is the 1-day last-seen window versus a single crawl round I guess.
achow101 vs fish.foo (both run dnsseedrs; willcl-ark’s fish.foo is a fork of achow’s). fish.foo’s good clearnet set (5,899) contains 96% of achow’s (4,250); the shared hosts make up 69% of fish.foo’s set, so fish.foo has about 1,800 hosts that achow does not. I think the remaining gap is vantage, uptime history and probe timing. Also fish.foo is some commits ahead, mostly packaging, performance and crawl scheduling.
DNS responses vs a full crawl
I also checked whether pooling DNS answers over time can stand in for a full dump in a clearnet census. Over 14 days (6h cadence, all nine seeds), against the btcnodes clearnet set of 2026-07-21, with recall[1] and precision[2]:
window
unique clearnet IPs
recall
precision
1d
2,996
23%
67%
3d
6,565
47%
62%
7d
9,693
61%
56%
14d
12,394
68%
48%
The pooled set grows into the thousands, but precision falls as older answers stay in the union. Size-dependent metrics (groups-to-50%, bucketing ratios) also change with sample size, so a DNS pool and a full crawl are different inputs. But maybe for the seeder-side full view, the published seeds.txt files (like from fish.foo, achow101) could be used.
DNS seed coverage
Also here is the share of IPv4 addresses each seed served on 2026-07-20 that appear in the crawlers’ clearnet sets from 2026-07-21, plus a reachability check from octavio.xyz.
The point of the archive was to put one clearnet basis under the sources in the list above. With that in hand, two things stand out for me.
First, raw “node counts” across sites are different objects. KIT / bitnod.es / btcnodes land near 9k clearnet hosts under their own rules. Seeder good sets are smaller because they score uptime over 2h…30d. For a population series I would pick one rule and keep it: a btcnodes snapshot, or bitnod.es last-seen with a fixed window and a 7-day mean.
Second, sharing a software line still leaves a measurable gap. bitnod.es and btcnodes agree on 88% and 93% of their respective sets, and of the bitnod.es-only hosts that day, about a third never show up in a week of btcnodes snapshots. For achow101 and fish.foo, 96% of achow’s good hosts are in fish.foo’s set, but fish.foo carries about 1,800 hosts achow does not.
Everything regenerates from the raw archives with two scripts in analysis/ of the bitcoin-seeder-data repo. If a number looks wrong from your side, I would like to know.
share of the btcnodes set that the pooled DNS answers cover ↩︎
share of the pooled DNS answers that appear in the btcnodes set ↩︎
Thank you! This is a great compilation of the different data sources.
A clarification about the KIT dossiers: All peers contained in a dossier are active and connected to the monitor at the time of creation of the dossier. The lastConnect field indicates when each connection was initiated. Assuming that now is the time of the dossier, this means the connections with lastConnect < now - 7d are active connections that have already existed for more than seven days while connections with lastConnect > now - 1d are connections that have been initiated within the last 24 hours.
Hey @jorisstrakeljahn this is great, love that you’re looking right at the start, that is, the interaction a node has when it is spun up for the first time.
A short note on the roughly 9k clearnet figures above: as discussed in #121, bitnod.es and btcnodes each include about 950 reachable endpoints from the same AS63949 fleet. They complete the Bitcoin handshake but do not behave like normal Bitcoin Core nodes afterward.
And thanks for the link, @deadmanoz. I hadn’t seen this implementation before. I’ll take a closer look and may include it in my crawler comparison.
Strakeljahn · 
Matthias Grundmann · 
Deadmanoz ·