瀏覽器會隱藏 www 子網域，www 子網域看起來會跟沒有 www 的根網域一模一樣。所以使用 www 子網域的時候應該要確保輸入根網域的時候也會重新導向到 www，才不會讓使用者輸入網址時不知道為何無法載入。
例如：架站服務 Netlify 預設指派 www 子網域給網站的時候會同時指派根網域。
If you assign an apex domain or a www subdomain to your site, Netlify will automatically add both the apex domain and the www subdomain.
— https://docs.netlify.com/domains-https/custom-domains/configure-external-dns/
以下是有 www 子網域但是造訪根網域時會除錯的常用臺灣網站，依 Tranco 排行排序。
最近更新：2025-09-15T16:07:11.019Z
這些網站有 www 子網域，瀏覽器上看起來像是沒有 www，但是照瀏覽器上所顯示的輸入時會出錯。
| Tranco 排行 | 網站 | |
|---|---|---|
| #1986 | ||
| #14695 | ||
| #12783 | ||
| #19658 | ||
| #19797 | ||
| #20757 | ||
| #23228 | ||
| #23710 | ||
| #26239 | ||
| #28092 | ||
| #29343 | ||
| #29884 | ||
| #31451 | ||
| #31951 | ||
| #31988 | ||
| #32714 | ||
| #35880 | ||
| #36676 | ||
| #36514 | ||
| #37316 | ||
| #37886 | ||
| #40143 | ||
| #40853 | ||
| #44786 | ||
| #45840 | ||
| #45613 | ||
| #46996 | ||
| #46258 | ||
| #53390 | ||
| #54983 | ||
| #55792 | ||
| #55742 | ||
| #55434 | ||
| #56255 | ||
| #57515 | ||
| #59078 | ||
| #59930 | ||
| #60036 | ||
| #61765 | ||
| #62017 | ||
| #62384 | ||
| #63753 | ||
| #64246 | ||
| #64854 | ||
| #65426 | ||
| #65180 | ||
| #66036 | ||
| #65541 | ||
| #69520 | ||
| #71199 | ||
| #71783 | ||
| #72719 | ||
| #71325 | ||
| #74346 | ||
| #73148 | ||
| #76083 | ||
| #76597 | ||
| #77371 | ||
| #77836 | ||
| #79139 | ||
| #80644 | ||
| #81644 | ||
| #82842 | ||
| #84114 | ||
| #86684 | ||
| #90999 | ||
| #92712 | ||
| #92944 | ||
| #94828 | ||
| #94804 | ||
| #95344 | ||
| #98369 | ||
| #98678 | ||
| #99841 | ||
| #103464 | ||
| #105695 | ||
| #107112 | ||
| #107920 | ||
| #109112 | ||
| #111172 | ||
| #112224 | ||
| #113040 | ||
| #116859 | ||
| #120469 | ||
| #121468 | ||
| #122843 | ||
| #124751 | ||
| #126907 | ||
| #127094 | ||
| #127873 | ||
| #126166 | ||
| #127987 | ||
| #126329 | ||
| #128368 | ||
| #131469 | ||
| #132732 | ||
| #133549 | ||
| #133364 | ||
| #134709 | ||
| #135289 | ||
| #135881 | ||
| #137052 | ||
| #137402 | ||
| #137405 | ||
| #137950 | ||
| #140557 | ||
| #142849 | ||
| #143401 | ||
| #143557 | ||
| #144845 | ||
| #147615 | ||
| #147679 | ||
| #149990 | ||
| #154237 | ||
| #157452 | ||
| #159672 | ||
| #159860 | ||
| #160553 | ||
| #161754 | ||
| #162782 | ||
| #164517 | ||
| #164740 | ||
| #165442 | ||
| #166786 | ||
| #164779 | ||
| #167485 | ||
| #165247 | ||
| #169876 | ||
| #170353 | ||
| #170368 | ||
| #170500 | ||
| #170868 | ||
| #172094 | ||
| #172237 | ||
| #173716 | ||
| #174737 | ||
| #176131 | ||
| #177397 | ||
| #177347 | ||
| #177951 | ||
| #178423 | ||
| #180762 | ||
| #179351 | ||
| #179232 | ||
| #181559 | ||
| #183069 | ||
| #185460 | ||
| #187718 | ||
| #188904 | ||
| #189180 | ||
| #189810 | ||
| #192108 | ||
| #192763 | ||
| #193280 | ||
| #196379 | ||
| #197091 | ||
| #198495 | ||
| #199517 | ||
| #200654 | ||
| #202059 | ||
| #206963 | ||
| #206986 | ||
| #207618 | ||
| #206615 | ||
| #207925 | ||
| #208994 | ||
| #212008 | ||
| #215605 | ||
| #215818 | ||
| #216164 | ||
| #216293 | ||
| #216243 | ||
| #220153 | ||
| #220762 | ||
| #221813 | ||
| #222049 | ||
| #220180 | ||
| #225129 | ||
| #225615 | ||
| #229142 | ||
| #235810 | ||
| #237065 | ||
| #236903 | ||
| #237899 | ||
| #238360 | ||
| #240011 | ||
| #240050 | ||
| #249161 | ||
| #251029 | ||
| #251482 | ||
| #254459 | ||
| #254895 | ||
| #257058 | ||
| #258217 | ||
| #258557 | ||
| #258721 | ||
| #260575 | ||
| #263151 | ||
| #268751 | ||
| #268656 | ||
| #271378 | ||
| #274279 | ||
| #276131 | ||
| #275365 | ||
| #281743 | ||
| #288287 | ||
| #293732 | ||
| #292380 | ||
| #297322 | ||
| #297682 | ||
| #298719 | ||
| #302955 | ||
| #303783 | ||
| #309796 | ||
| #310938 | ||
| #310424 | ||
| #316720 | ||
| #317093 | ||
| #317199 | ||
| #317322 | ||
| #319288 | ||
| #320403 | ||
| #321703 | ||
| #324260 | ||
| #324456 | ||
| #327376 | ||
| #328316 | ||
| #328824 | ||
| #328491 | ||
| #331820 | ||
| #336788 | ||
| #338500 | ||
| #338790 | ||
| #338705 | ||
| #342601 | ||
| #343015 | ||
| #342590 | ||
| #344623 | ||
| #346103 | ||
| #346136 | ||
| #347412 | ||
| #348028 | ||
| #349199 | ||
| #349511 | ||
| #353678 | ||
| #355058 | ||
| #356046 | ||
| #361574 | ||
| #365480 | ||
| #365900 | ||
| #368283 | ||
| #367631 | ||
| #367946 | ||
| #370498 | ||
| #373899 | ||
| #375753 | ||
| #375570 | ||
| #378594 | ||
| #378747 | ||
| #380671 | ||
| #380872 | ||
| #384702 | ||
| #385561 | ||
| #390841 | ||
| #398066 | ||
| #399671 | ||
| #400293 | ||
| #400513 | ||
| #400840 | ||
| #401535 | ||
| #402003 | ||
| #406873 | ||
| #409496 | ||
| #409962 | ||
| #410552 | ||
| #413277 | ||
| #414907 | ||
| #419084 | ||
| #420234 | ||
| #420598 | ||
| #427890 | ||
| #431776 | ||
| #433429 | ||
| #432299 | ||
| #434409 | ||
| #434745 | ||
| #436714 | ||
| #436885 | ||
| #437094 | ||
| #439158 | ||
| #440179 | ||
| #443280 | ||
| #447496 | ||
| #451629 | ||
| #451801 | ||
| #455111 | ||
| #456058 | ||
| #457607 | ||
| #457515 | ||
| #458022 | ||
| #458877 | ||
| #459672 | ||
| #460335 | ||
| #460841 | ||
| #461876 | ||
| #462042 | ||
| #462846 | ||
| #465803 | ||
| #465336 | ||
| #474111 | ||
| #475955 | ||
| #480086 | ||
| #483851 | ||
| #481725 | ||
| #484163 | ||
| #486086 | ||
| #487966 | ||
| #487699 | ||
| #489581 | ||
| #490807 | ||
| #490994 | ||
| #493968 | ||
| #496172 | ||
| #495499 | ||
| #500687 | ||
| #502108 | ||
| #504842 | ||
| #507292 | ||
| #505597 | ||
| #509320 | ||
| #516102 | ||
| #516970 | ||
| #517354 | ||
| #518150 | ||
| #518655 | ||
| #520455 | ||
| #520294 | ||
| #533789 | ||
| #534289 | ||
| #534795 | ||
| #536537 | ||
| #539268 | ||
| #540914 | ||
| #542144 | ||
| #542206 | ||
| #542464 | ||
| #543352 | ||
| #547415 | ||
| #550805 | ||
| #551624 | ||
| #552066 | ||
| #554448 | ||
| #556085 | ||
| #554212 | ||
| #558899 | ||
| #559287 | ||
| #559939 | ||
| #557606 | ||
| #561607 | ||
| #562427 | ||
| #563930 | ||
| #565424 | ||
| #566122 | ||
| #568084 | ||
| #567726 | ||
| #570376 | ||
| #571690 | ||
| #574309 | ||
| #575164 | ||
| #580211 | ||
| #581339 | ||
| #579202 | ||
| #581882 | ||
| #585370 | ||
| #588917 | ||
| #589207 | ||
| #589623 | ||
| #588177 | ||
| #591026 | ||
| #595832 | ||
| #595928 | ||
| #596906 | ||
| #596432 | ||
| #597186 | ||
| #600289 | ||
| #600617 | ||
| #603710 | ||
| #601719 | ||
| #604990 | ||
| #607675 | ||
| #608983 | ||
| #615900 | ||
| #616589 | ||
| #620824 | ||
| #620913 | ||
| #625634 | ||
| #631138 | ||
| #634075 | ||
| #637216 | ||
| #636554 | ||
| #642118 | ||
| #644024 | ||
| #648086 | ||
| #650609 | ||
| #651547 | ||
| #657145 | ||
| #657912 | ||
| #658462 | ||
| #660344 | ||
| #662078 | ||
| #662182 | ||
| #663788 | ||
| #666945 | ||
| #667026 | ||
| #667283 | ||
| #668072 | ||
| #669572 | ||
| #670640 | ||
| #671626 | ||
| #671544 | ||
| #673548 | ||
| #676312 | ||
| #677105 | ||
| #682171 | ||
| #683795 | ||
| #688378 | ||
| #694850 | ||
| #703146 | ||
| #708699 | ||
| #712766 | ||
| #712776 | ||
| #716283 | ||
| #716360 | ||
| #717767 | ||
| #717931 | ||
| #717949 | ||
| #721254 | ||
| #721463 | ||
| #721526 | ||
| #722580 | ||
| #722613 | ||
| #727565 | ||
| #729604 | ||
| #730317 | ||
| #730432 | ||
| #730549 | ||
| #730415 | ||
| #731298 | ||
| #731536 | ||
| #730769 | ||
| #733784 | ||
| #734691 | ||
| #737863 | ||
| #738009 | ||
| #738578 | ||
| #737817 | ||
| #741171 | ||
| #742891 | ||
| #742938 | ||
| #746811 | ||
| #747868 | ||
| #748098 | ||
| #748614 | ||
| #748682 | ||
| #748765 | ||
| #749094 | ||
| #749816 | ||
| #749458 | ||
| #750413 | ||
| #751710 | ||
| #751959 | ||
| #754567 | ||
| #756704 | ||
| #756522 | ||
| #757639 | ||
| #757951 | ||
| #758089 | ||
| #758553 | ||
| #759898 | ||
| #759456 | ||
| #760574 | ||
| #760461 | ||
| #760686 | ||
| #761295 | ||
| #762653 | ||
| #762016 | ||
| #763935 | ||
| #764422 | ||
| #766597 | ||
| #766888 | ||
| #767340 | ||
| #767180 | ||
| #768296 | ||
| #768521 | ||
| #768775 | ||
| #768689 | ||
| #768831 | ||
| #768780 | ||
| #768717 | ||
| #768946 | ||
| #769458 | ||
| #769835 | ||
| #770551 | ||
| #771015 | ||
| #771218 | ||
| #772106 | ||
| #772536 | ||
| #774046 | ||
| #774598 | ||
| #775084 | ||
| #775163 | ||
| #775192 | ||
| #775888 | ||
| #775720 | ||
| #775930 | ||
| #776723 | ||
| #777742 | ||
| #778097 | ||
| #778350 | ||
| #779287 | ||
| #779961 | ||
| #781350 | ||
| #782988 | ||
| #783279 | ||
| #783277 | ||
| #784387 | ||
| #784906 | ||
| #785376 | ||
| #785390 | ||
| #785920 | ||
| #785962 | ||
| #786850 | ||
| #787579 | ||
| #787647 | ||
| #788213 | ||
| #793053 | ||
| #794375 | ||
| #794725 | ||
| #795903 | ||
| #796323 | ||
| #796918 | ||
| #797398 | ||
| #798321 | ||
| #798311 | ||
| #798762 | ||
| #801428 | ||
| #801695 | ||
| #802477 | ||
| #803761 | ||
| #803933 | ||
| #805752 | ||
| #806002 | ||
| #806717 | ||
| #807785 | ||
| #807824 | ||
| #807879 | ||
| #809119 | ||
| #809129 | ||
| #809258 | ||
| #808576 | ||
| #812486 | ||
| #812781 | ||
| #813360 | ||
| #813793 | ||
| #815012 | ||
| #815088 | ||
| #815702 | ||
| #816213 | ||
| #817621 | ||
| #818830 | ||
| #819318 | ||
| #820929 | ||
| #823203 | ||
| #821457 | ||
| #824640 | ||
| #828976 | ||
| #829509 | ||
| #831736 | ||
| #829771 | ||
| #833053 | ||
| #833635 | ||
| #836901 | ||
| #840749 | ||
| #842026 | ||
| #842636 | ||
| #842344 | ||
| #847689 | ||
| #850152 | ||
| #854749 | ||
| #860401 | ||
| #861350 | ||
| #866140 | ||
| #866502 | ||
| #867191 | ||
| #867813 | ||
| #871742 | ||
| #874700 | ||
| #874975 | ||
| #882537 | ||
| #883188 | ||
| #882820 | ||
| #885780 | ||
| #885024 | ||
| #896608 | ||
| #897539 | ||
| #901562 | ||
| #902375 | ||
| #905055 | ||
| #906971 | ||
| #909682 | ||
| #910024 | ||
| #922520 | ||
| #922516 | ||
| #925085 | ||
| #930650 | ||
| #934360 | ||
| #940366 | ||
| #944379 | ||
| #948787 | ||
| #949420 | ||
| #949180 | ||
| #956327 | ||
| #959914 | ||
| #962820 | ||
| #969701 | ||
| #973442 | ||
| #974150 | ||
| #966805 | ||
| #981323 | ||
| #998277 |
Cloudflare 說明文件：DNS record types
若主要使用的網址是 www.example.com，要讓 example.com 重新導向到主網址：
如果 DNS 提供者像 Cloudflare 一樣支援 CNAME flattening，可以直接新增一個 CNAME 紀錄：
@www.example.comCNAME 紀錄一般無法用於根網域，此時可以自行複製 www 子網域的 A 紀錄，例如 www 指向 0.0.0.0 時只要再建立一個 A 紀錄： 便會
@0.0.0.0造訪 example.com 時便會跟 www.example.com 時解析成同一個 IP 位址。
之後再從伺服器回傳 302 或 307 重新導向到主網址。
作：如月飛羽；設計參考 Why No HTTPS.