oppalerts.com →
Site Information

gbt.org

Link authority for gbt.org (registrable domain: gbt.org) from the Common Crawl web graph: PageRank and harmonic centrality history since 2017, current scores, and the site's top backlink sources.

13Domain PageRank
25Host Backlinks
193Domain Backlinks
Link authority data (PageRank, harmonic centrality) and backlinks come from the Common Crawl web graph.
gbt_org.profile
Current Scores

Web-graph authority (0-100)

Domain scores measure gbt.org as a whole: every subdomain's links rolled up into one node of Common Crawl's domain-level web graph. Host scores measure the exact hostname gbt.org. WWW scores cover the www variant of that hostname, which the graph tracks as its own entry since January 2026 (before that, www and bare host were merged). A big gap between domain and host usually means the domain's authority lives on other subdomains. PageRank is link-endorsement authority: how much weight the sites linking here carry themselves. Harmonic centrality measures reach: how close this site sits to the rest of the web when following links, which favors broadly connected sites over ones boosted by a few heavy linkers. All are normalized 0 to 100 within each crawl snapshot; a dash means that series does not exist for this site.

13
Domain PageRank
3
Host PageRank
-
WWW PageRank
95
Domain Harmonic Centrality
94
Host Harmonic Centrality
-
WWW Harmonic Centrality
Site Intelligence

Homepage

What gbt.org presents on its own homepage: the page title, description, and the social share markup it publishes. Pulled from https://gbt.org.

TitleETS- Great Books Education
DescriptionEscondido Tutorial Service delivers Great Books education to homeschool families through the Internet and localy.
Site Intelligence

Social accounts and contact points

Where this site maintains a presence and every reachable route its homepage exposes: social accounts, contact pages, addresses, and content feeds.

Web-Graph History

Authority over time

Every Common Crawl web-graph release since 2017, roughly quarterly. The domain series goes back to 2017; Common Crawl only began publishing the host-level graph in 2020, so host lines start there. Click a legend entry to show or hide that line. Flat lines are normal for established sites; watch for sustained rises or drops, which track real gains or losses in who links here.

A note on www: through the end of 2025 the source web graph merged www and non-www hostnames into the bare name, so one host line covers both. Starting in January 2026 the graph splits them into separate entries, which is why www can carry its own scores going forward.

Backlink Data

Backlink counts

Unique linking domains seen in Common Crawl's link graphs. This is a different dataset than the 0-100 authority scores above: these are raw counts, host-level for gbt.org and domain-level for gbt.org with all its subdomains combined. Common Crawl covers a large sample of the web, not all of it, so treat counts as comparable between sites rather than absolute totals.

25
Host Backlinks
193
Domain Backlinks
Backlink Data

Top backlinks in the domain graph

Common Crawl publishes two link graphs. The DOMAIN graph connects whole domains: every link from any page of one domain to any page of another. This table shows the highest-authority domains linking to gbt.org (including its subdomains), ranked by the linker's PageRank. The table shows the top 193; the download carries the full stored list (up to 10,000 linkers) as JSON. Click a linker for its own site profile.

Download domain backlinks (.json)

Linking SiteLinker PageRankLinker Harmonic Centrality
adobe.com9148
wikipedia.org9053
blogspot.com8648
cmu.edu7741
princeton.edu7643
wikidot.com6838
ning.com6838
hawaii.edu6837
pbworks.com6636
hypothes.is6236
elte.hu6236
thegospelcoalition.org6034
aleteia.org6034
nedbatchelder.com6034
johndcook.com5926
fee.org5834
boardhost.com5834
newworldencyclopedia.org5735
straightdope.com5634
firstthings.com5634
thenewatlantis.com5534
dyne.org5524
homeschool-life.com5424
challies.com5024
salon24.pl4933
intellectualtakeout.org4924
sabda.org4834
str.org4834
acton.org4825
brighthubeducation.com4733
vdare.com4634
classicalconversations.com4633
hsc.edu4624
armstrongeconomics.com4534
ccwatershed.org4533
mereorthodoxy.com4533
masters.edu4524
cathyduffyreviews.com4323
wmbriggs.com4224
hea.edu.au4133
home-school.com4133
wdtprs.com4024
classroom20.com4024
raisinglifelonglearners.com3922
romanroadspress.com3833
blackledge.com3722
mondaymorningmemo.com3623
successfulstudent.org3423
simplehomeschool.net3322
catholicliberaleducation.org3322
christianhumanist.org3224
johnredwoodsdiary.com3223
benandme.com3222
home-ed.vic.edu.au3123
jennifermarohasy.com3123
ichoosejoy.org3023
metaglossary.com3022
amnation.com2923
charlottemasonpoetry.org2922
sylviamartinez.com2920
exodusmandate.org2823
thecurriculumchoice.com2723
versindaba.co.za2623
mises.ro2523
donpotter.net2523
tgcchinese.org2523
whatdoesthismean.org2522
eastghost.com2423
targuman.org2422
homeschoolingtorah.com2419
keywen.com2323
familystyleschooling.com2322
mhjb.co.nz2322
oakleys.org.uk2319
karenglass.net2122
preachthestory.com2122
tuttlesvc.org2122
andreazuvich.com2023
illinoisloop.org2023
wisdomhomeschooling.com2022
kingsclassical.org2021
flipcamp.org2020
transformingteachers.org1922
cscmovement.org1921
worldbusinesspromote.com1918
claphamschool.org1823
michellevanloon.com1822
anneelliott.com1822
northwindinstitute.org1819
homeschoolinginflorida.com1818
keithbuhler.com1721
brainsandcareers.com1720
educatedclimber.com1718
cdtschool.org1717
reasoned.org1623
freechristianresources.org1622
parnassusprep.com1620
therestfulhome.com1617
oslcpagosa.org1523
logosmedia.com1522
thepersonalistproject.org1522
trinitychristian.net1517
seghea.com1423
graceandgreenpastures.com1422
austinclassical.org1417
biblicalhomeschooling.org1417
bradfordacademy.org1323
eukaryaacademy.com1323
goodmanson.com1322
benespen.com1322
nomoz.org1322
platoscave.org1322
homeschoolingbg.com1322
regentsacademy.com1317
romeofthewest.com1223
greyfriarstutorials.org1212
sttheophanacademy.com1122
acontinualfeast.com1122
pcsvirginia.org1119
lourdesclassical.org1117
thisisourstory.net1022
thistlecove.farm1022
homeschoolinginlouisiana.com1017
cornerstonesalina.com1013
myharvardclassics.com923
salemsattic.com922
homeschool.co.uk922
canadianliberty.com922
mikedvirgilio.com919
homeschoolinginkentucky.com917
rhetoricring.com917
homeschoolinginvirginia.com917
columbusclassical.org910
excelsiorclassical.org823
thebcca.org817
cfssd.org813
davoh.org722
one-eternal-day.com722
funarg.org718
homeschoolingingeorgia.com717
homeschoolingindc.com717
homeschoolinginillinois.com717
homeschoolinginmaryland.com717
homeschoolinginrhodeisland.com713
highlandssummerville.org713
homeschoolinginmassachusetts.com713
vineyardhomeschoolfellowship.com70
oddlysaid.com622
jeneralities.com622
organarchy.net621
chriskelley.org617
iapologia.com617
homeschoolinginindiana.com613
trinitasclassical.org612
homeschoolinginalabama.com612
homeschoolinginwashington.com612
cedarclassicalacademy.org611
homeschoolingintennessee.com610
intrepidlutherans.com522
homeschoolinginsouthcarolina.com517
thee.ca517
homeschoolingindelaware.com517
collegiumstudycenter.org513
homeschoolinginidaho.com513
homeschoolinginarkansas.com512
homeschoolingincolorado.com512
homeschoolinginnebraska.com512
ournomadichomestead.com511
homeschoolinginohio.com511
homeschoolinginoregon.com510
homeschoolinginutah.com510
homeschoolinginwestvirginia.com510
homeschoolinginvermont.com510
homeschoolinginminnesota.com510
homeschoolinginarizona.com510
homeschoolinginoklahoma.com510
homeschoolinginwyoming.com58
homeschoolinginkansas.com58
schola-tutorials.com422
thankfulhouse.com417
ceanet.net413
homeschoolinginwisconsin.com410
homeschoolinginmaine.com410
homeschoolinginnorthdakota.com48
virtuscottageschool.com40
sjcacademy.com313
polymathclassical.com312
materdeiacademy.org38
humanbecoming.ca213
patrickhalbrook.com213
stoicacademia.com28
chambersclassical.org012
exploringcharacter.com00
Backlink Data

Top backlinks in the host graph

The HOST graph connects exact hostnames, so subdomains count separately. This table shows the highest-authority hosts linking to gbt.org specifically, ranked by the linker's PageRank. The table shows the top 25; the download carries the full stored list (up to 10,000 linkers) as JSON. Click a linker for its own site profile.

Download host backlinks (.json)