Log status

Every usable Certificate Transparency log is read from two directions at once: the head follows new entries as they are published, while the backfill works forward from entry zero. When the two meet, that log is fully covered.

The bar shows how much of a log's history has been read: under a third, under two thirds, most of the way, fully covered.

A marks a log whose head is delivering entries right now. Every live log is followed continuously, but the tail only records progress when a log actually publishes something, so a log that has been silent for more than fifteen minutes drops out of the list of live ones.

Logs marked archived were shut down and no longer serve anything. They are read from local copies of the ct-archive preservation of them on the Internet Archive, in the same format the log itself published.

126Logs
72,454,407,189Entries read
23,429,058,710Entries remaining
86,308,085,401Entries published
Live Log Type Tree size Backfilled Head Coverage
✓ Google 'Argon2026h2' log rfc6962 3,451,089,321 1,741,605,121 3,451,089,321 50%
✓ TrustAsia 'log2026b' rfc6962 3,023,579,769 827,320,321 3,023,579,769 27%
✓ TrustAsia 'log2026a' rfc6962 3,002,700,699 1,141,078,529 3,002,700,699 38%
✓ Google 'Xenon2026h2' log rfc6962 2,984,360,518 2,238,191,616 2,984,360,518 74%
✓ Sectigo 'Tiger2026h2' rfc6962 2,444,667,421 2,396,800,130 2,444,667,421 complete
✓ DigiCert 'Wyvern2026h2' rfc6962 2,177,953,252 1,403,896,833 2,177,953,252 64%
✓ DigiCert 'Sphinx2026h2' rfc6962 2,144,983,244 1,316,556,033 2,144,983,244 61%
✓ Sectigo 'Elephant2026h2' rfc6962 2,048,072,254 2,008,942,848 2,048,072,254 complete
✓ Google 'ParcelYard2026h2' log tiled 1,610,636,666 1,533,153,648 1,610,636,666 complete
✓ Google 'PlumbersArms2026h2' log tiled 1,610,149,504 1,532,731,937 1,610,149,504 complete
✓ IPng Networks 'Halloumi2026h2a' tiled 1,263,198,335 1,211,326,256 1,263,198,335 complete
✓ IPng Networks 'Gouda2026h2' tiled 1,226,302,492 1,187,343,784 1,226,302,492 complete
✓ DigiCert 'Wyvern 2026h1' Log rfc6962 1,217,972,030 404,914,433 1,217,972,030 33%
✓ DigiCert 'Sphinx 2026h1' Log rfc6962 1,100,493,968 387,716,865 1,100,493,968 35%
✓ Let's Encrypt 'Sycamore2026h2' tiled 1,029,466,321 982,191,721 1,029,466,321 complete
✓ Geomys 'Tuscolo2026h2' tiled 1,011,062,707 945,262,156 1,011,062,707 complete
✓ Let's Encrypt 'Willow2026h2' tiled 986,917,844 941,188,215 986,917,844 complete
✓ Let's Encrypt 'Sycamore2027h1' tiled 720,941,064 411,958,346 720,941,064 complete
✓ Let's Encrypt 'Willow2027h1' tiled 717,651,564 414,380,012 717,651,564 complete
✓ Google 'Argon2027h1' rfc6962 646,955,590 358,083,769 646,955,590 complete
✓ Sectigo 'Tiger2027h1' rfc6962 527,857,694 281,394,590 527,857,694 complete
✓ Google 'Xenon2027h1' rfc6962 519,557,885 247,454,830 519,557,885 complete
✓ Sectigo 'Elephant2027h1' rfc6962 513,582,385 264,482,304 513,582,385 complete
✓ Google 'PlumbersArms2027h1' log tiled 389,062,768 79,831,994 389,062,768 complete
✓ Google 'ParcelYard2027h1' log tiled 388,216,290 79,879,925 388,216,290 complete
✓ TrustAsia 'HETU2027' rfc6962 384,636,284 183,970,968 384,636,284 complete
✓ TrustAsia Luoshu2027 tiled 381,497,031 183,033,088 381,488,384 complete
✓ Geomys 'Tuscolo2027h1' tiled 307,963,558 102,147,265 307,963,558 complete
✓ DigiCert 'Wyvern2027h1' rfc6962 291,107,746 162,583,884 291,107,746 complete
✓ DigiCert 'sphinx2027h1' rfc6962 255,483,212 138,037,056 255,483,212 complete
✓ IPng Networks 'Halloumi2027h1' tiled 235,609,725 98,450,739 235,609,725 complete
✓ IPng Networks 'Gouda2027h1' tiled 200,004,783 79,053,452 200,004,783 complete
✓ Microsec Eszigno2027h1 tiled 21,826,517 45,734 21,826,517 complete
✓ Microsec Eszigno2026h2 tiled 19,369,410 2,153,932 19,369,410 complete
✓ Geomys 'Tuscolo2027h2' tiled 78,624 46,126 78,624 complete
✓ Geomys Tuscolo2028h1 tiled 55,237 22,644 55,237 complete
✓ Geomys Tuscolo2028h2 tiled 55,187 22,670 55,187 complete
✓ Sectigo 'Elephant2027h2' rfc6962 31,989 30,733 31,989 complete
✓ IPng Networks 'Halloumi2027h2' tiled 19,866 18,641 19,866 complete
✓ IPng Networks Halloumi2028h1 tiled 2,638 1,330 2,638 complete
✓ IPng Networks Gouda2028h2 tiled 2,588 1,349 2,588 complete
✓ IPng Networks Halloumi2028h2 tiled 2,580 1,341 2,580 complete
✓ Microsec Eszigno2028h1 tiled 2,166 882 2,166 complete
Cloudflare 'Nimbus2026' rfc6962 6,710,347,142 61,282,305 6,710,347,142 0%
Google 'Argon 2026H1' log rfc6962 2,807,501,296 1,176,163,584 2,807,501,296 41%
Google 'Xenon 2026H1' log rfc6962 2,542,706,695 1,591,461,376 2,542,706,695 62%
Elephant 2026h1 rfc6962 2,054,351,766 2,054,351,766 2,054,351,766 complete
Tiger 2026h1 rfc6962 2,002,576,673 2,002,576,673 2,002,576,673 complete
DigiCert Yeti2025 Log archived 1,967,320,888 1,967,320,888 — complete
Gouda 2026h1 tiled 1,544,673,809 1,544,673,809 1,544,673,809 complete
IPng GmbH 'Halloumi2026h1' tiled 1,467,336,774 1,467,336,774 1,467,336,774 complete
Cloudflare 'Nimbus2023' Log archived 1,328,497,706 1,328,497,706 — complete
tiger2025h2.ct.sectigo.com archived 1,254,180,709 1,254,180,709 — complete
elephant2025h2.ct.sectigo.com archived 1,227,732,310 1,227,732,310 — complete
Sectigo 'Sabre2025h2' archived 1,213,760,848 1,213,760,848 — complete
Let's Encrypt 'Oak2023' log archived 1,074,253,152 1,074,253,152 — complete
DigiCert 'Wyvern2025h2' Log archived 1,016,240,650 1,016,240,650 — complete
DigiCert 'Sphinx2025h2' Log archived 1,012,539,029 1,012,539,029 — complete
Let's Encrypt 'Oak2025h1' archived 990,630,759 990,630,759 — complete
Cloudflare 'Nimbus2024' Log archived 962,089,707 962,089,707 — complete
log.willow.ct.letsencrypt.org/2026h1 tiled 926,067,188 926,067,188 926,067,188 complete
log.sycamore.ct.letsencrypt.org/2026h1 tiled 926,062,388 926,062,388 926,062,388 complete
DigiCert Nessie2025 Log archived 881,954,985 881,954,985 — complete
DigiCert Yeti2022-2 Log archived 873,631,884 873,631,884 — complete
Sectigo 'Mammoth2025h2' archived 865,235,451 865,235,451 — complete
Cloudflare 'Nimbus2022' Log archived 805,190,170 805,190,170 — complete
Sectigo 'Mammoth' CT log archived 798,400,519 798,400,519 — complete
Cloudflare 'Raio2026h2a' log tiled 736,674,196 709,224,998 736,674,196 complete
Cloudflare 'Nimbus2027' rfc6962 625,734,362 59,912,449 625,734,362 9%
Let's Encrypt 'Oak2026h1' archived 598,614,696 598,614,696 — complete
Let's Encrypt 'Oak2020' log archived 566,652,310 566,652,310 — complete
Let's Encrypt 'Oak2019' log archived 559,850,441 559,850,441 — complete
Sectigo 'Sabre' CT log archived 546,099,887 546,099,887 — complete
Cloudflare 'Raio2026h1a' log tiled 520,044,352 520,044,352 520,044,352 complete
Let's Encrypt 'Oak2022' log archived 494,549,333 494,549,333 — complete
TrustAsia Log2025B (RFC6962) archived 484,346,197 484,346,197 — complete
TrustAsia Log2025A (RFC6962) archived 422,712,902 422,712,902 — complete
Let's Encrypt 'Oak2021' log archived 365,301,134 365,301,134 — complete
Sectigo 'Mammoth2024h2' archived 306,636,641 306,636,641 — complete
DigiCert Yeti2021 Log archived 305,279,032 305,279,032 — complete
DigiCert Yeti2019 Log archived 293,281,869 293,281,869 — complete
DigiCert Nessie2023 Log archived 287,166,870 287,166,870 — complete
Sectigo 'Sabre2024h2' archived 279,774,157 279,774,157 — complete
DigiCert 'Wyvern2025h1' Log archived 276,121,828 276,121,828 — complete
DigiCert 'Sphinx2025h1' Log archived 275,557,396 275,557,396 — complete
Tuscolo2026h1 tiled 229,562,122 229,562,122 229,562,122 complete
DigiCert Yeti2020 Log archived 207,205,755 207,205,755 — complete
Sectigo 'Sabre2024h1' archived 188,922,977 188,922,977 — complete
DigiCert Nessie2022 Log archived 162,451,767 162,451,767 — complete
Cloudflare 'Raio2027h1a' log tiled 154,390,741 118,131,359 154,390,741 complete
Let's Encrypt 'Oak2026h2' archived 130,815,692 130,815,692 — complete
Venafi Gen2 CT log archived 111,554,066 111,554,066 — complete
DigiCert Yeti2023 Log archived 106,052,098 106,052,098 — complete
DigiCert Nessie2018 Log archived 102,686,882 102,686,882 — complete
DigiCert Nessie2021 Log archived 99,117,500 99,117,500 — complete
DigiCert Yeti2018 Log archived 90,785,920 90,785,920 — complete
DigiCert Log Server 2 archived 90,271,162 90,271,162 — complete
Sectigo 'Sabre2026h1' archived 88,744,205 88,744,205 — complete
Trust Asia Log2024-2 archived 76,472,679 76,472,679 — complete
Sectigo 'Sabre2026h2' archived 68,732,793 68,732,793 — complete
DigiCert Yeti2022 Log archived 65,551,225 65,551,225 — complete
Sectigo 'Mammoth2026h1' archived 65,240,567 65,240,567 — complete
Sectigo 'Mammoth2026h2' archived 57,634,084 57,634,084 — complete
Sectigo 'Mammoth2024h1' archived 32,062,981 32,062,981 — complete
DigiCert 'Wyvern2024h2' Log archived 30,255,475 30,255,475 — complete
DigiCert 'Sphinx2024h2' Log archived 30,208,759 30,208,759 — complete
DigiCert Nessie2020 Log archived 28,387,332 28,387,332 — complete
DigiCert Log Server archived 24,897,274 24,897,274 — complete
Symantec log archived 9,426,803 9,426,803 — complete
Symantec 'Vega' log archived 1,673,300 1,673,300 — complete
Symantec 'Sirius' log archived 1,403,918 1,403,918 — complete
DigiCert Nessie2019 Log archived 428,788 428,788 — complete
DigiCert 'Wyvern2024h1' Log archived 50,541 50,541 — complete
DigiCert 'Sphinx2024h1' Log archived 34,637 34,637 — complete
DigiCert 'Wyvern2027h2' rfc6962 33,450 31,177 33,450 complete
DigiCert 'sphinx2027h2' rfc6962 33,380 31,105 33,380 complete
Sectigo 'Tiger2027h2' rfc6962 31,296 30,067 31,296 complete
IPng Networks 'Gouda2027h2' tiled 20,091 18,871 20,091 complete
Let's Encrypt 'Willow2027h2' tiled 20,073 18,842 20,073 complete
Let's Encrypt 'Sycamore2027h2' tiled 20,051 18,814 20,051 complete
Cloudflare 'Raio2027h2a' log tiled 19,331 18,689 19,331 complete
Google 'PlumbersArms2027h2' log tiled 9,019 7,795 9,019 complete
Google 'ParcelYard2027h2' log tiled 8,993 7,762 8,993 complete
IPng Networks Gouda2028h1 tiled 2,627 1,326 2,627 complete
Microsec Eszigno2028h2 tiled 2,120 880 2,120 complete
Microsec Eszigno2027h2 tiled 2,100 883 2,100 complete