Open CDN detection tool

www.pypi.org CDN Detection: Possible Fastly Usage

CNAME, HTTP header, and ASN signals indicate that www.pypi.org may be using Fastly, with 65% confidence. Review the evidence and latest check time.

Checked At: 11/4/2026, 09:25:25

Likely using Fastly

This result is based on public DNS, HTTP, and network signals and may update with later observations.

www.pypi.orgHTTP Status 200 11/4/2026, 09:25:25

Overall Confidence

65%Evidence strength

Based on the independent evidence matched in this detection

Node Distribution

Current snapshot
Fastly 65%

Detection Path

Complete · 5 stages

DNS Resolution
-

Complete · 6 addresses

CNAME Chain
-

Complete · 1 CNAME found

IP / ASN
-

Complete · 6 IPs, 4 ASNs

HTTP Response
-

Complete · response headers collected

Fingerprint Score
-

Complete · 4 evidence types

Evidence Timeline

Observed facts ordered by collection time

Checked At: 11/4/2026, 09:25:25
01:25:25 AM
CNAME
CNAME: dualstack.python.map.fastly.net
Fastly

Unknown

01:25:25 AM
HTTP
header: x-served-by
Fastly

Strong

01:26:42 AM
HTTP
header: x-served-by
Fastly

Strong

01:26:42 AM
CNAME
CNAME: dualstack.python.map.fastly.net
Fastly

Unknown

01:26:42 AM
HTTP
header: x-served-by
Fastly

Strong

Show 9 more evidence items
01:26:42 AM
CNAME
CNAME: dualstack.python.map.fastly.net
Fastly

Unknown

01:26:42 AM
HTTP
header: x-served-by
Fastly

Strong

01:26:42 AM
CNAME
CNAME: dualstack.python.map.fastly.net
Fastly

Unknown

01:26:42 AM
HTTP
header: x-served-by
Fastly

Strong

01:26:42 AM
CNAME
CNAME: dualstack.python.map.fastly.net
Fastly

Unknown

01:26:43 AM
CNAME
CNAME: dualstack.python.map.fastly.net
Fastly

Unknown

01:26:43 AM
HTTP
header: x-served-by
Fastly

Strong

01:26:44 AM
CNAME
CNAME: dualstack.python.map.fastly.net
Fastly

Unknown

01:26:44 AM
HTTP
header: x-served-by
Fastly

Strong

Score Explanation

Evidence strength breakdown

CNAME evidence
100 / 100

CNAME target and routing-domain signals

HTTP headers
100 / 100

Response header name and value matches

This score presents evidence strength, not statistical probability. A shared ASN or cloud network cannot confirm a CDN on its own.

Node and Routing Differences

Resolution results and access signals observed by region and carrier

Collected just now
RegionCarrierResolved IPCDN ProviderASNLocationTTLConfidenceTTFB
Northern China中国电信151.101.192.223/32Fastly-中国 北京市-
65%
2764ms
Central node-151.101.192.223/32Fastly--59s
65%
-
East AsiaOverseas151.101.128.223/32Fastly-中国香港特别行政区 香港-
65%
111ms
Western North AmericaOverseas151.101.64.223/32Fastly-美国 圣何塞-
65%
132ms
North America-151.101.128.223/32Fastly-美国 洛杉矶-
65%
90ms
Southwestern China中国电信2a04:4e42:400::223/128Fastly-中国 昆明市-
65%
1122ms
Southern ChinaBGP多线151.101.192.223/32Fastly-中国 广州市-
65%
2198ms
Node results vary by region, carrier and time7 nodes
Detection results are inferred from public DNS and HTTP signals. Confidence reflects the strength of the matched evidence and does not imply 100% certainty.
FastlyPrimary candidate

Confidence 65%

CNAME: dualstack.python.map.fastly.net
header: x-served-by
CNAME: dualstack.python.map.fastly.net
header: x-served-by
CNAME: dualstack.python.map.fastly.net
header: x-served-by
CNAME: dualstack.python.map.fastly.net
header: x-served-by
CNAME: dualstack.python.map.fastly.net
header: x-served-by
CNAME: dualstack.python.map.fastly.net
header: x-served-by
CNAME: dualstack.python.map.fastly.net
header: x-served-by
View Fastly Performance Review

Methodology and limitations

Identification results are determined by cross-referencing public DNS, HTTP response headers, and ASN signals; confidence indicates the strength of evidence and does not represent statistical accuracy.