www.amazon.co.jp Open in urlscan Pro
2600:140b:1c00:5ad::3bd0  Public Scan

0 Outgoing links

These are links going to different origins than the main page.

Redirected requests

There were HTTP redirect chains for the following requests:

11 HTTP transactions Everything HTML Script AJAX CSS Image Expand all
0 data transactions

Method Protocol	Status	Resource Path	Size x-fer	Time Latency	Type MIME-Type	IP Location
GET H2	200	Primary Request editPaymentPreference Show response www.amazon.co.jp/gp/primecentral/	7 KB 3 KB	136ms 116ms	Document text/html	2600:140b:1c00:5ad::3bd0 AKAMAI-ASN1 Akama...
General Check archive.org Show headers Download Go to Full URL https://www.amazon.co.jp/gp/primecentral/editPaymentPreference?ie=UTF8&ref_=pe_36136612_488236302_pe_bp_subscriptionPlanID_update&&H=RQVAQOILTXAGUAX1BDL3USDFAHOA&ref_=pe_36136612_488236302_pe_bp_subscriptionPlanID_update Protocol H2 Security TLS 1.3, , AES_128_GCM Server 2600:140b:1c00:5ad::3bd0 Tokyo, Japan, ASN20940 (AKAMAI-ASN1 Akamai International B.V., NL), Reverse DNS Software Server / Resource Hash 3e45d90679b0fe0d0c37bdfb4639e54af891571cc6825e93120ac15f160759fe Security Headers Name Value Strict-Transport-Security max-age=47474747; includeSubDomains; preload Request headers Upgrade-Insecure-Requests 1 User-Agent Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.36 Response headers alt-svc h3=":443"; ma=93600 content-encoding gzip content-length 2467 content-type text/html date Sun, 15 Dec 2024 05:42:12 GMT server Server strict-transport-security max-age=47474747; includeSubDomains; preload vary Content-Type,Accept-Encoding,User-Agent x-amz-rid 8VWH5SZHZVQK3YCRKVKE x-amzn-cdn-id ak-0.9933d417.1734241332.69dae02 x-cache NotCacheable from child
GET H2	200	AmazonUI-3c913031596ca78a3768f4e934b1cc02ce238101.secure.min._V1_.css images-na.ssl-images-amazon.com/images/G/01/AUIClients/	165 KB 19 KB	48ms 4ms	Stylesheet text/css	2a04:4e42:600::272 FASTLY
General Check archive.org Show headers Download Go to Full URL https://images-na.ssl-images-amazon.com/images/G/01/AUIClients/AmazonUI-3c913031596ca78a3768f4e934b1cc02ce238101.secure.min._V1_.css Requested by Host: www.amazon.co.jp URL: https://www.amazon.co.jp/gp/primecentral/editPaymentPreference?ie=UTF8&ref_=pe_36136612_488236302_pe_bp_subscriptionPlanID_update&&H=RQVAQOILTXAGUAX1BDL3USDFAHOA&ref_=pe_36136612_488236302_pe_bp_subscriptionPlanID_update Protocol H2 Security TLS 1.3, , AES_128_GCM Server 2a04:4e42:600::272 , United States, ASN54113 (FASTLY, US), Reverse DNS Software / Resource Hash 5ab7636e9f2e3ad10acc3d81e7ef8bf615504699d42034c041ff9e7c93f178bb Request headers User-Agent Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.36 Referer https://www.amazon.co.jp/ Response headers x-amz-ir-id 7b2d87d8-20b9-474e-be4e-a3c2a07e9757 content-encoding br age 4136067 expires Sun, 27 Sep 2043 12:40:24 GMT server-timing provider;desc="fy" x-cache HIT from fastly, HIT from fastly alt-svc h3=":443";ma=86400,h3-29=":443";ma=86400,h3-27=":443";ma=86400 date Sun, 15 Dec 2024 05:42:12 GMT content-type text/css vary Accept-Encoding x-nginx-cache-status HIT last-modified Wed, 17 Jul 2013 22:49:32 GMT x-served-by cache-iad-kjyo7100147-IAD, cache-nrt-rjtf7700032-NRT cache-control max-age=630720000,public timing-allow-origin https://www.amazon.co.jp accept-ranges bytes access-control-allow-origin * content-length 18915
GET H2	200	Captcha_chvqswmhjr.jpg images-na.ssl-images-amazon.com/captcha/cucusdhr/	6 KB 6 KB	47ms 5ms	Image image/jpeg	2a04:4e42:600::272 FASTLY
General Check archive.org Show headers Download Go to Show image Full URL https://images-na.ssl-images-amazon.com/captcha/cucusdhr/Captcha_chvqswmhjr.jpg Requested by Host: www.amazon.co.jp URL: https://www.amazon.co.jp/gp/primecentral/editPaymentPreference?ie=UTF8&ref_=pe_36136612_488236302_pe_bp_subscriptionPlanID_update&&H=RQVAQOILTXAGUAX1BDL3USDFAHOA&ref_=pe_36136612_488236302_pe_bp_subscriptionPlanID_update Protocol H2 Security TLS 1.3, , AES_128_GCM Server 2a04:4e42:600::272 , United States, ASN54113 (FASTLY, US), Reverse DNS Software / Resource Hash f3a5af698b59894a7853061f886933205baa66f8ed720bbb6e718f3a1ae795f4 Request headers User-Agent Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.36 Referer https://www.amazon.co.jp/ Response headers x-amz-ir-id fa20c671-1bf5-40c2-8254-9edff1c08cd2 alt-svc h3=":443";ma=86400,h3-29=":443";ma=86400,h3-27=":443";ma=86400 timing-allow-origin https://www.amazon.co.jp age 171751 accept-ranges bytes access-control-allow-origin * x-cache HIT from fastly, HIT from fastly content-length 6095 server-timing provider;desc="fy" date Sun, 15 Dec 2024 05:42:12 GMT content-type image/jpeg last-modified Wed, 08 Feb 2012 17:14:51 GMT x-nginx-cache-status MISS x-served-by cache-iad-kjyo7100047-IAD, cache-nrt-rjtf7700032-NRT
GET H2	200	requestId=8VWH5SZHZVQK3YCRKVKE&js=1 fls-fe.amazon.co.jp/1/oc-csi/1/OP/	43 B 151 B	390ms 129ms	Image image/gif	35.163.1.145 AMAZON-02
General Check archive.org Show headers Download Go to Show image Full URL https://fls-fe.amazon.co.jp/1/oc-csi/1/OP/requestId=8VWH5SZHZVQK3YCRKVKE&js=1 Requested by Host: www.amazon.co.jp URL: https://www.amazon.co.jp/gp/primecentral/editPaymentPreference?ie=UTF8&ref_=pe_36136612_488236302_pe_bp_subscriptionPlanID_update&&H=RQVAQOILTXAGUAX1BDL3USDFAHOA&ref_=pe_36136612_488236302_pe_bp_subscriptionPlanID_update Protocol H2 Security TLS 1.2, ECDHE_RSA, AES_128_GCM Server 35.163.1.145 Boardman, United States, ASN16509 (AMAZON-02, US), Reverse DNS ec2-35-163-1-145.us-west-2.compute.amazonaws.com Software / Resource Hash a3a64aea2e96ec58a163ddb8d4cf86cf236178ed2d225b8f44154bc1b010ddce Request headers User-Agent Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.36 Referer https://www.amazon.co.jp/ Response headers x-amzn-requestid fbc3f9f6-39f6-4cfc-8fc0-d6f53d6e3f14 content-length 43 date Sun, 15 Dec 2024 05:42:13 GMT content-type image/gif
GET H2	200	csm-captcha-instrumentation.min.js Show response images-fe.ssl-images-amazon.com/images/G/01/csminstrumentation/	2 KB 1 KB	9ms 4ms	Script application/x-javascript	2a04:4e42:600::272 FASTLY
General Check archive.org Show headers Download Go to Full URL https://images-fe.ssl-images-amazon.com/images/G/01/csminstrumentation/csm-captcha-instrumentation.min.js Requested by Host: www.amazon.co.jp URL: https://www.amazon.co.jp/gp/primecentral/editPaymentPreference?ie=UTF8&ref_=pe_36136612_488236302_pe_bp_subscriptionPlanID_update&&H=RQVAQOILTXAGUAX1BDL3USDFAHOA&ref_=pe_36136612_488236302_pe_bp_subscriptionPlanID_update Protocol H2 Security TLS 1.3, , AES_128_GCM Server 2a04:4e42:600::272 , United States, ASN54113 (FASTLY, US), Reverse DNS Software / Resource Hash 35cf72b3f65845c32617eb726119bbdd969738b7d62bb760c4381e82ce37ac4a Request headers User-Agent Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.36 Referer https://www.amazon.co.jp/ Response headers x-amz-ir-id c6a962be-5dd5-45b1-80a9-50fbdaaef369 content-encoding br age 50025 expires Thu, 07 Dec 2023 04:13:48 GMT server-timing provider;desc="fy" x-cache HIT from fastly, HIT from fastly alt-svc h3=":443";ma=86400,h3-29=":443";ma=86400,h3-27=":443";ma=86400 date Sun, 15 Dec 2024 05:42:12 GMT content-type application/x-javascript vary Accept-Encoding x-nginx-cache-status HIT last-modified Mon, 12 Oct 2015 09:22:39 GMT x-served-by cache-iad-kcgs7200088-IAD, cache-nrt-rjtf7700032-NRT cache-control max-age=86400,public timing-allow-origin https://www.amazon.co.jp accept-ranges bytes access-control-allow-origin * content-length 821
GET H2	200	rd-script-6d68177fa6061598e9509dc4b5bdd08d.js Show response images-fe.ssl-images-amazon.com/images/G/01/csminstrumentation/	2 KB 856 B	8ms 3ms	Script application/x-javascript	2a04:4e42:600::272 FASTLY
General Check archive.org Show headers Download Go to Full URL https://images-fe.ssl-images-amazon.com/images/G/01/csminstrumentation/rd-script-6d68177fa6061598e9509dc4b5bdd08d.js Requested by Host: www.amazon.co.jp URL: https://www.amazon.co.jp/gp/primecentral/editPaymentPreference?ie=UTF8&ref_=pe_36136612_488236302_pe_bp_subscriptionPlanID_update&&H=RQVAQOILTXAGUAX1BDL3USDFAHOA&ref_=pe_36136612_488236302_pe_bp_subscriptionPlanID_update Protocol H2 Security TLS 1.3, , AES_128_GCM Server 2a04:4e42:600::272 , United States, ASN54113 (FASTLY, US), Reverse DNS Software / Resource Hash 0a7e3153f44d0e51c73dad9fa3034a14446bedbafc38e477915382dd02269123 Request headers User-Agent Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.36 Referer https://www.amazon.co.jp/ Response headers x-amz-ir-id b62d12d7-7331-40ee-b9ac-911cedf2a8f9 content-encoding br age 66922 expires Wed, 25 Oct 2023 22:21:21 GMT server-timing provider;desc="fy" x-cache HIT from fastly, HIT from fastly alt-svc h3=":443";ma=86400,h3-29=":443";ma=86400,h3-27=":443";ma=86400 date Sun, 15 Dec 2024 05:42:12 GMT content-type application/x-javascript vary Accept-Encoding x-nginx-cache-status HIT last-modified Fri, 20 Mar 2020 12:31:03 GMT x-served-by cache-iad-kcgs7200080-IAD, cache-nrt-rjtf7700032-NRT cache-control max-age=86400,public timing-allow-origin https://www.amazon.co.jp accept-ranges bytes access-control-allow-origin * content-length 661
GET H2	200	aui_sprite_0007-1x._V383827579_.png images-na.ssl-images-amazon.com/images/G/01/amazonui/sprites/	17 KB 17 KB	5ms 3ms	Image image/png	2a04:4e42:600::272 FASTLY
General Check archive.org Show headers Download Go to Show image Full URL https://images-na.ssl-images-amazon.com/images/G/01/amazonui/sprites/aui_sprite_0007-1x._V383827579_.png Requested by Host: images-na.ssl-images-amazon.com URL: https://images-na.ssl-images-amazon.com/images/G/01/AUIClients/AmazonUI-3c913031596ca78a3768f4e934b1cc02ce238101.secure.min._V1_.css Protocol H2 Security TLS 1.3, , AES_128_GCM Server 2a04:4e42:600::272 , United States, ASN54113 (FASTLY, US), Reverse DNS Software / Resource Hash 49ff798368f6e4367d03a44af687d47609ca4608d02b1a099281f88c910cf1aa Request headers User-Agent Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.36 Referer https://images-na.ssl-images-amazon.com/images/G/01/AUIClients/AmazonUI-3c913031596ca78a3768f4e934b1cc02ce238101.secure.min._V1_.css Response headers x-amz-ir-id 69bbf9fd-7c82-4c13-a437-b7b0ec452875 age 4120194 expires Sun, 27 Sep 2043 14:31:13 GMT alt-svc h3=":443";ma=86400,h3-29=":443";ma=86400,h3-27=":443";ma=86400 x-cache HIT from fastly, HIT from fastly server-timing provider;desc="fy" date Sun, 15 Dec 2024 05:42:12 GMT content-type image/png last-modified Wed, 15 May 2013 01:55:34 GMT x-nginx-cache-status HIT x-served-by cache-iad-kcgs7200051-IAD, cache-nrt-rjtf7700032-NRT cache-control max-age=630720000,public timing-allow-origin https://www.amazon.com accept-ranges bytes access-control-allow-origin * content-length 16972
GET H3	200	ue-base-1c399ad9886cab69575e1e5ee15c61a1._V313498596_.js Show response images-na.ssl-images-amazon.com/images/G/01/csminstrumentation/	7 KB 3 KB	5ms 4ms	Script application/x-javascript	151.101.1.16 FASTLY
General Check archive.org Show headers Download Go to Full URL https://images-na.ssl-images-amazon.com/images/G/01/csminstrumentation/ue-base-1c399ad9886cab69575e1e5ee15c61a1._V313498596_.js Requested by Host: images-fe.ssl-images-amazon.com URL: https://images-fe.ssl-images-amazon.com/images/G/01/csminstrumentation/csm-captcha-instrumentation.min.js Protocol H3 Security QUIC, , AES_256_GCM Server 151.101.1.16 San Francisco, United States, ASN54113 (FASTLY, US), Reverse DNS Software / Resource Hash a538a2b295512c2a3b74f63e74047db79140733da941fb0fca2b95a1dfdada37 Request headers User-Agent Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.36 Referer https://www.amazon.co.jp/ Response headers x-amz-ir-id 01f39f96-813d-42cd-8675-cdb9b95ef464 content-encoding br age 3440572 expires Thu, 27 Mar 2042 07:23:38 GMT server-timing provider;desc="fy" x-cache HIT from fastly, HIT from fastly alt-svc h3=":443";ma=86400,h3-29=":443";ma=86400,h3-27=":443";ma=86400 date Sun, 15 Dec 2024 05:42:12 GMT content-type application/x-javascript vary Accept-Encoding x-nginx-cache-status HIT last-modified Wed, 26 Aug 2015 14:52:49 GMT x-served-by cache-iad-kiad7000053-IAD, cache-nrt-rjtf7700053-NRT cache-control max-age=630720000,public timing-allow-origin https://www.amazon.co.jp accept-ranges bytes access-control-allow-origin * content-length 2871
GET H3	200	ClientSideMetricsAUIJavascript-51171fbdd28e1a7a61e922e8f0272af8bc74d37b.secure.variant-desktop-session-snapshot-keypress.min._V2_.js Show response images-na.ssl-images-amazon.com/images/G/01/AUIClients/	19 KB 7 KB	4ms 3ms	Script application/x-javascript	151.101.1.16 FASTLY
General Check archive.org Show headers Download Go to Full URL https://images-na.ssl-images-amazon.com/images/G/01/AUIClients/ClientSideMetricsAUIJavascript-51171fbdd28e1a7a61e922e8f0272af8bc74d37b.secure.variant-desktop-session-snapshot-keypress.min._V2_.js Requested by Host: images-fe.ssl-images-amazon.com URL: https://images-fe.ssl-images-amazon.com/images/G/01/csminstrumentation/csm-captcha-instrumentation.min.js Protocol H3 Security QUIC, , AES_256_GCM Server 151.101.1.16 San Francisco, United States, ASN54113 (FASTLY, US), Reverse DNS Software / Resource Hash 877c2c2a2da0a1a6c0ad0d7ac8071046a1d726e5ab9c63509e3786b8c8ec5042 Request headers User-Agent Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.36 Referer https://www.amazon.co.jp/ Response headers x-amz-ir-id d6f55b63-8437-46cd-895d-3623a35aeb3b content-encoding br age 3424806 expires Mon, 07 Sep 2043 01:00:28 GMT server-timing provider;desc="fy" x-cache HIT from fastly, HIT from fastly alt-svc h3=":443";ma=86400,h3-29=":443";ma=86400,h3-27=":443";ma=86400 date Sun, 15 Dec 2024 05:42:12 GMT content-type application/x-javascript vary Accept-Encoding x-nginx-cache-status HIT last-modified Thu, 01 Oct 2015 10:17:43 GMT x-served-by cache-iad-kjyo7100078-IAD, cache-nrt-rjtf7700053-NRT cache-control max-age=630720000,public timing-allow-origin https://www.amazon.co.jp accept-ranges bytes access-control-allow-origin * content-length 7138
GET H2	200	favicon.ico www.amazon.co.jp/	17 KB 3 KB	11ms 9ms	Other image/x-icon	2600:140b:1c00:5ad::3bd0 AKAMAI-ASN1 Akama...
General Check archive.org Show headers Download Go to Full URL https://www.amazon.co.jp/favicon.ico Protocol H2 Security TLS 1.3, , AES_128_GCM Server 2600:140b:1c00:5ad::3bd0 Tokyo, Japan, ASN20940 (AKAMAI-ASN1 Akamai International B.V., NL), Reverse DNS Software Server / Resource Hash 17d02e2db6dbedb95dd449d06868c147ac2c3b5371497bcb9407e75336a99e09 Security Headers Name Value Strict-Transport-Security max-age=47474747; includeSubDomains; preload X-Content-Type-Options nosniff X-Frame-Options SAMEORIGIN Request headers User-Agent Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.36 Referer https://www.amazon.co.jp/gp/primecentral/editPaymentPreference?ie=UTF8&ref_=pe_36136612_488236302_pe_bp_subscriptionPlanID_update&&H=RQVAQOILTXAGUAX1BDL3USDFAHOA&ref_=pe_36136612_488236302_pe_bp_subscriptionPlanID_update Response headers content-encoding gzip etag "4486-490c87c5a6340" x-content-type-options nosniff alt-svc h3=":443"; ma=93600 x-cache Hit from child date Sun, 15 Dec 2024 05:42:13 GMT content-type image/x-icon vary Accept-Encoding last-modified Tue, 21 Sep 2010 17:37:41 GMT x-frame-options SAMEORIGIN strict-transport-security max-age=47474747; includeSubDomains; preload x-amzn-cdn-id ak-0.9933d417.1734241333.69daea8 x-amz-rid JXQ62DTBPA953WXAFHNM accept-ranges bytes content-length 2477 server Server
POST H2	204	/ fls-fe.amazon.co.jp/1/batch/1/OE/	0 177 B	210ms 204ms	Ping text/plain	35.163.1.145 AMAZON-02
General Check archive.org Show headers Download Go to Full URL https://fls-fe.amazon.co.jp/1/batch/1/OE/ Requested by Host: images-na.ssl-images-amazon.com URL: https://images-na.ssl-images-amazon.com/images/G/01/AUIClients/ClientSideMetricsAUIJavascript-51171fbdd28e1a7a61e922e8f0272af8bc74d37b.secure.variant-desktop-session-snapshot-keypress.min._V2_.js Protocol H2 Security TLS 1.2, ECDHE_RSA, AES_128_GCM Server 35.163.1.145 Boardman, United States, ASN16509 (AMAZON-02, US), Reverse DNS ec2-35-163-1-145.us-west-2.compute.amazonaws.com Software / Resource Hash e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855 Request headers User-Agent Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.36 Content-Type text/plain;charset=UTF-8 Referer https://www.amazon.co.jp/ Response headers x-amzn-requestid eb44bde8-eba8-4ceb-aed4-f5556ea0420f access-control-allow-origin * access-control-expose-headers x-amzn-RequestId,x-amzn-ErrorType,x-amzn-ErrorMessage,Date,smithy-protocol date Sun, 15 Dec 2024 05:42:14 GMT

31 JavaScript Global Variables

These are the non-standard "global" variables defined on the window object. These can be helpful in identifying possible client-side frameworks and code.

number| ue_t0 object| ue_csm object| ue string| ue_furl string| ue_mid string| ue_sid string| ue_sn string| ue_id object| head string| prefix object| elem object| ue_modules object| cel_widgets string| ue_cel_ns object| ue_err number| ueinit function| ues function| uet function| uex function| onLd function| onLdEnd function| onstop function| ueLogError object| ue_cel object| ue_pdm object| ue_vpm object| ue_fem object| ue_mcm object| ue_mmm object| ue_rpl object| ue_kpm

1 Cookies

Cookies are little pieces of information stored in the browser of a user. Whenever a user visits the site again, he will also send his cookie values, thus allowing the website to re-identify him even if he changed locations. This is how permanent logins work.

			Domain/Path	Expires	Name / Value
			www.amazon.co.jp/	1970-01-21 02:23:28	Name: csm-sid Value: 463-6502841-7215748

Security Headers

This page lists any security headers set by the main page. If you want to understand what these mean and how to use them, head on over to this page

Header	Value
Strict-Transport-Security	max-age=47474747; includeSubDomains; preload

Indicators

This is a term in the security industry to describe indicators such as IPs, Domains, Hashes, etc. This does not imply that any of these indicate malicious activity.

fls-fe.amazon.co.jp
images-fe.ssl-images-amazon.com
images-na.ssl-images-amazon.com
www.amazon.co.jp
151.101.1.16
2600:140b:1c00:5ad::3bd0
2a04:4e42:600::272
35.163.1.145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