[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"article:pixiv-image-cdn":3},{"meta":4,"markdown":67,"quiz":68},{"type":5,"articleId":6,"slug":7,"title":8,"titleEn":9,"category":10,"summary":11,"publishedAt":12,"image":13,"vocabulary":14,"quizId":66},"article","tech-pixiv-image-cdn","pixiv-image-cdn","pixivの画像配信基盤 — 数億イラストを世界に届ける技術","pixiv's Image CDN: Delivering Hundreds of Millions of Illustrations","tech","An overview of how pixiv — the illustration platform launched in 2007 and now hosting over 100 million works for 70 million users — built a global image-delivery stack on top of Fastly. Topics include WebP\u002FAVIF format adoption, age-gated R-18 content, on-the-fly resize variants, copyright watermarking, the Antique UI overhaul, mobile-app native support, and Korean\u002FChinese localized URLs for overseas expansion.\n","2026-04-28T00:00:00Z","https:\u002F\u002Fimages.yamiyomi.com\u002Ftech-pixiv-image-cdn.png",[15,20,24,28,33,37,42,46,50,54,58,62],{"word":16,"reading":17,"meaning":18,"level":19},"配信","はいしん","delivery","N2",{"word":21,"reading":22,"meaning":23,"level":19},"基盤","きばん","platform",{"word":25,"reading":26,"meaning":27,"level":19},"投稿","とうこう","post",{"word":29,"reading":30,"meaning":31,"level":32},"作品","さくひん","work (of art)","N3",{"word":34,"reading":35,"meaning":36,"level":19},"規模","きぼ","scale",{"word":38,"reading":39,"meaning":40,"level":41},"提携","ていけい","partnership","N1",{"word":43,"reading":44,"meaning":45,"level":19},"形式","けいしき","format",{"word":47,"reading":48,"meaning":49,"level":32},"対応","たいおう","support",{"word":51,"reading":52,"meaning":53,"level":32},"年齢","ねんれい","age",{"word":55,"reading":56,"meaning":57,"level":19},"制限","せいげん","restriction",{"word":59,"reading":60,"meaning":61,"level":41},"透かし","すかし","watermark",{"word":63,"reading":64,"meaning":65,"level":41},"展開","てんかい","expansion","tech-pixiv-image-cdn-quiz","\n::para\npixivは[2007]{にせんなな:2007}[年]{ねん:year:N5}に[誕生]{たんじょう:was born:N1}したイラスト[投稿]{とうこう:posting:N1}サイトであり、[現在]{げんざい:currently:N3}では[累計]{るいけい:cumulative:N1}[作品]{さくひん:works:N4}[数]{すう:number:N3}が[1億]{いちおく:100 million:N2}を[超え]{こえ:exceeding:N2}、[登録]{とうろく:registered:N2}ユーザーは[7000万]{ななせんまん:70 million:N5}に[達して]{たっして:reaching:N3}います。これだけの[規模]{きぼ:scale:N1}の[画像]{がぞう:images:N2}を[世界]{せかい:world:N4}[中]{じゅう:throughout:N5}に[安定]{あんてい:stably:N3}して[届ける]{とどける:deliver:N2}ため、[同社]{どうしゃ:the company:N4}は[専用]{せんよう:dedicated:N2}の[画像]{がぞう:image:N2}[配信]{はいしん:delivery:N3}[基盤]{きばん:platform:N1}を[構築]{こうちく:built:N2}しています。\n\n#en\npixiv is an illustration-posting site launched in 2007. Its cumulative work count now exceeds 100 million, and registered users have reached 70 million. To deliver images at this scale stably to a worldwide audience, the company has built a dedicated image-delivery platform.\n::\n\n::heading\nFastlyとの[提携]{ていけい:partnership:N1}\n\n#en\nPartnership with Fastly\n::\n\n::para\npixivは[長年]{ながねん:for many years:N5}、[米国]{べいこく:US:N3}のCDN[事業者]{じぎょうしゃ:vendor:N4}Fastlyと[提携]{ていけい:partnership:N1}し、[全世界]{ぜんせかい:worldwide:N3}に[配置]{はいち:deployed:N3}されたエッジサーバーから[画像]{がぞう:images:N2}を[配信]{はいしん:deliver:N3}しています。Fastlyの[特徴]{とくちょう:characteristic:N1}は、VCL（Varnish Configuration Language）による[柔軟]{じゅうなん:flexible:N2}な[制御]{せいぎょ:control:N3}と、[即時]{そくじ:instant:N1}キャッシュパージにあります。[新作]{しんさく:newly posted work:N4}が[投稿]{とうこう:submitted:N1}された[瞬間]{しゅんかん:moment:N1}から[数秒]{すうびょう:a few seconds:N2}で[全世界]{ぜんせかい:worldwide:N3}のエッジに[配信]{はいしん:delivered:N3}される[仕組み]{しくみ:mechanism:N3}です。\n\n#en\nFor many years pixiv has partnered with the US-based CDN vendor Fastly, delivering images from edge servers deployed worldwide. Fastly's strengths are flexible control via VCL (Varnish Configuration Language) and instant cache purging. The mechanism delivers a newly submitted work to edges around the world within a few seconds of posting.\n::\n\n::heading\nWebP・AVIFへの[対応]{たいおう:adoption:N1}\n\n#en\nAdopting WebP and AVIF\n::\n\n::para\nイラストは[一般]{いっぱん:general:N2}の[写真]{しゃしん:photos:N4}と[比べ]{くらべ:compared to:N2}、[平坦]{へいたん:flat:N1}な[色]{いろ:color:N4}[領域]{りょういき:regions:N2}が[多く]{おおく:many:N4}、[圧縮]{あっしゅく:compression:N1}[効率]{こうりつ:efficiency:N1}が[高い]{たかい:high:N5}という[特性]{とくせい:characteristic:N3}があります。pixivはJPEG・PNGに[加え]{くわえ:in addition to:N3}、WebPおよびAVIF[形式]{けいしき:format:N3}にも[対応]{たいおう:supports:N1}しており、ブラウザの`Accept`ヘッダを[見て]{みて:looking at:N5}[最適]{さいてき:optimal:N3}な[形式]{けいしき:format:N3}をエッジで[選択]{せんたく:select:N1}します。AVIFは[同等]{どうとう:equivalent:N3}[画質]{がしつ:quality:N4}でJPEGの[半分]{はんぶん:half:N5}[以下]{いか:or less:N4}の[容量]{ようりょう:file size:N2}に[収まる]{おさまる:fits within:N3}ため、[転送]{てんそう:transfer:N4}[量]{りょう:volume:N2}と[読み込み]{よみこみ:loading:N3}[時間]{じかん:time:N5}を[大幅]{おおはば:significantly:N2}に[削減]{さくげん:reduce:N1}できます。\n\n#en\nCompared to typical photos, illustrations have many flat color regions, giving them high compression efficiency. In addition to JPEG and PNG, pixiv supports WebP and AVIF, with the edge selecting the optimal format based on the browser's Accept header. Because AVIF fits equivalent visual quality into less than half the size of JPEG, it significantly reduces both transfer volume and load time.\n::\n\n::callout\n[要点]{ようてん:key point:N3}：[同じ]{おなじ:same:N4}URLでも、ブラウザによって[返される]{かえされる:returned:N3}[画像]{がぞう:image:N2}[形式]{けいしき:format:N3}は[異なります]{ことなります:differs:N1}。`Vary: Accept`ヘッダで[正しく]{ただしく:correctly:N4}キャッシュを[分離]{ぶんり:separate:N1}することが[必須]{ひっす:essential:N1}です。\n\n#en\nKey point: For the same URL, the returned image format may differ by browser. Correctly separating the cache via the `Vary: Accept` header is essential.\n::\n\n::heading\n[年齢]{ねんれい:age:N2}[制限]{せいげん:restriction:N3}コンテンツのCDN[戦略]{せんりゃく:strategy:N2}\n\n#en\nCDN Strategy for Age-Restricted Content\n::\n\n::para\npixivには[一般]{いっぱん:general:N2}[作品]{さくひん:works:N4}と[並んで]{ならんで:alongside:N2}、R-18と[呼ばれる]{よばれる:called:N3}[成人]{せいじん:adult:N3}[向け]{むけ:for:N3}コンテンツが[多数]{たすう:many:N3}[投稿]{とうこう:posted:N1}されています。これらは[未成年]{みせいねん:minors:N3}や[未]{み:not yet:N3}[ログイン]{ろぐいん:logged-in}ユーザーには[配信]{はいしん:deliver:N3}してはなりません。エッジサーバーは[Cookie]{くっきー:cookie}と[認証]{にんしょう:authentication:N1}トークンを[検査]{けんさ:inspect:N1}し、[年齢]{ねんれい:age:N2}[確認]{かくにん:verification:N3}[済み]{ずみ:completed:N3}のユーザーにのみオリジン[サーバー]{さーばー:server}へ[転送]{てんそう:forward:N4}します。[未]{み:not yet:N3}[認証]{にんしょう:authenticated:N1}リクエストはエッジで[即座]{そくざ:immediately:N1}に[拒否]{きょひ:rejected:N1}され、オリジンに[負荷]{ふか:load:N2}を[かけません]{かけません:does not put}。\n\n#en\nAlongside general works, pixiv hosts a large amount of adult content known as R-18. These must not be delivered to minors or logged-out users. Edge servers inspect cookies and authentication tokens, forwarding to the origin only for users who have completed age verification. Unauthenticated requests are rejected immediately at the edge, avoiding any load on the origin.\n::\n\n::heading\nオンザフライ[リサイズ]{りさいず:resize}\n\n#en\nOn-The-Fly Resize\n::\n\n::para\n[同じ]{おなじ:same:N4}[作品]{さくひん:work:N4}でも、サムネイル、[一覧]{いちらん:list:N1}[表示]{ひょうじ:display:N3}、[詳細]{しょうさい:detail:N1}[表示]{ひょうじ:display:N3}、[拡大]{かくだい:full-size:N1}[表示]{ひょうじ:display:N3}など[用途]{ようと:use case:N3}に[応じて]{おうじて:according to:N1}[多数]{たすう:many:N3}のサイズが[必要]{ひつよう:required:N3}です。pixivはアップロード[時]{じ:at time of:N5}に[全]{ぜん:all:N3}サイズを[事前]{じぜん:in advance:N4}[生成]{せいせい:generate:N3}するのではなく、URLにサイズ[指定]{してい:specification:N3}を[含め]{ふくめ:include:N2}、エッジで[初回]{しょかい:first time:N3}リクエスト[時]{じ:at time of:N5}にリサイズして[結果]{けっか:result:N1}をキャッシュします。これにより[使われない]{つかわれない:unused:N4}サイズの[生成]{せいせい:generation:N3}コストを[回避]{かいひ:avoid:N1}し、[新しい]{あたらしい:new:N4}[端末]{たんまつ:device:N1}[解像度]{かいぞうど:resolutions:N2}にも[即座]{そくざ:instantly:N1}に[対応]{たいおう:support:N1}できます。\n\n#en\nEven for the same work, many sizes are required depending on the use case — thumbnails, list views, detail views, full-size views, and so on. Rather than pre-generating all sizes at upload time, pixiv encodes the size specification into the URL and resizes at the edge on the first request, then caches the result. This avoids the cost of generating unused sizes and instantly supports new device resolutions.\n::\n\n::heading\n[著作権]{ちょさくけん:copyright:N2}[保護]{ほご:protection:N1}と[透かし]{すかし:watermark:N1}\n\n#en\nCopyright Protection and Watermarking\n::\n\n::para\n[投稿]{とうこう:posted:N1}された[作品]{さくひん:works:N4}が[無断]{むだん:without permission:N3}で[転載]{てんさい:reposted:N1}されることを[防ぐ]{ふせぐ:prevent:N2}ため、pixivは[一部]{いちぶ:some:N3}の[配信]{はいしん:delivery:N3}[経路]{けいろ:paths:N3}で[半透明]{はんとうめい:semi-transparent:N1}の[透かし]{すかし:watermark:N1}を[画像]{がぞう:image:N2}に[合成]{ごうせい:composite onto:N3}しています。[特に]{とくに:especially:N4}[未]{み:not yet:N3}[ログイン]{ろぐいん:logged-in}ユーザーや[海外]{かいがい:overseas:N4}IPからの[アクセス]{あくせす:access}に[対して]{たいして:toward:N3}は、[作者]{さくしゃ:author:N4}[名]{めい:name:N5}とpixivロゴを[薄く]{うすく:lightly:N2}[重ねた]{かさねた:overlaid:N4}バージョンを[返す]{かえす:return:N3}ことで、スクレイピングへの[抑止]{よくし:deterrent:N1}としています。\n\n#en\nTo prevent posted works from being reposted without permission, pixiv composites a semi-transparent watermark onto images on certain delivery paths. Particularly for logged-out users and accesses from overseas IPs, the platform returns a version with the author's name and the pixiv logo lightly overlaid, serving as a deterrent against scraping.\n::\n\n::callout\n[注意]{ちゅうい:caution:N4}：[透かし]{すかし:watermark:N1}は[正規]{せいき:legitimate:N3}ユーザーの[鑑賞]{かんしょう:appreciation:N1}[体験]{たいけん:experience:N4}を[損なう]{そこなう:harm:N2}ため、ログイン[後]{ご:after:N5}は[原則]{げんそく:in principle:N2}として[透かし]{すかし:watermark:N1}なしの[画像]{がぞう:image:N2}が[配信]{はいしん:delivered:N3}されます。\n\n#en\nCaution: Watermarks harm the viewing experience for legitimate users, so as a rule, watermark-free images are delivered after login.\n::\n\n::heading\n[新]{しん:new:N4}UI「アンティーク」プロジェクト\n\n#en\nThe \"Antique\" New-UI Project\n::\n\n::para\n2010[年代]{ねんだい:decade:N4}[後半]{こうはん:latter half:N5}、pixivは「アンティーク」と[呼ばれる]{よばれる:called:N3}[大規模]{だいきぼ:large-scale:N1}UI[改善]{かいぜん:overhaul:N1}プロジェクトを[実施]{じっし:carried out:N1}しました。これに[伴い]{ともない:accompanying:N1}、[従来]{じゅうらい:conventionally:N1}の[固定]{こてい:fixed:N2}サイズ[画像]{がぞう:image:N2}URLは[廃止]{はいし:abolished:N1}され、レスポンシブな[多]{た:multiple:N4}[解像度]{かいぞうど:resolution:N2}URLへ[移行]{いこう:migrated:N2}しました。[既存]{きそん:existing:N1}URLとの[互換]{ごかん:compatibility:N2}を[保つ]{たもつ:maintain:N1}ため、エッジで[古い]{ふるい:old:N4}URLを[新しい]{あたらしい:new:N4}URLへ[内部的]{ないぶてき:internally:N3}に[書き換える]{かきかえる:rewrite:N2}リダイレクト[層]{そう:layer:N2}が[追加]{ついか:added:N3}されています。\n\n#en\nIn the latter half of the 2010s, pixiv carried out a large-scale UI overhaul project called \"Antique.\" With this, the conventional fixed-size image URLs were abolished and migrated to responsive multi-resolution URLs. To maintain compatibility with existing URLs, a redirect layer was added at the edge that internally rewrites old URLs into new ones.\n::\n\n::heading\nモバイルアプリへの[ファースト]{ふぁーすと:first}パーティ[対応]{たいおう:support:N1}\n\n#en\nFirst-Party Support for Mobile Apps\n::\n\n::para\npixivの[公式]{こうしき:official:N3}iOS\u002FAndroidアプリは、ブラウザとは[別]{べつ:separate:N4}の[配信]{はいしん:delivery:N3}[最適化]{さいてきか:optimization:N3}を[受け取って]{うけとって:receiving:N3}います。[端末]{たんまつ:device:N1}[情報]{じょうほう:information:N3}に[基づき]{もとづき:based on:N1}、Retina[相当]{そうとう:equivalent:N3}の[端末]{たんまつ:device:N1}には2倍[解像度]{かいぞうど:resolution:N2}を、[低速]{ていそく:slow:N2}[回線]{かいせん:network:N2}には[低]{てい:low:N2}[ビットレート]{びっとれーと:bitrate}AVIFを[配信]{はいしん:deliver:N3}するなど、[端末]{たんまつ:device:N1}[特性]{とくせい:characteristics:N3}に[応じた]{おうじた:according to:N1}[出し]{だし:serving:N5}[分け]{わけ:differentiation:N5}を[エッジ]{えっじ:edge}で[行います]{おこないます:perform:N5}。\n\n#en\npixiv's official iOS\u002FAndroid apps receive delivery optimizations distinct from those for browsers. Based on device information, the edge differentiates serving — sending 2x resolution to Retina-class devices, low-bitrate AVIF to slow networks, and so on, tailored to device characteristics.\n::\n\n::heading\n[海外]{かいがい:overseas:N4}[展開]{てんかい:expansion:N1}とローカライズURL\n\n#en\nOverseas Expansion and Localized URLs\n::\n\n::para\npixivは[韓国]{かんこく:Korea:N2}、[台湾]{たいわん:Taiwan:N2}、[中国]{ちゅうごく:China:N5}など[アジア]{あじあ:Asia}[圏]{けん:region:N1}で[強い]{つよい:strong:N4}[人気]{にんき:popularity:N5}を[誇り]{ほこり:enjoying:N1}、それぞれの[地域]{ちいき:region:N2}に[最適化]{さいてきか:optimized:N3}されたCDNエッジを[活用]{かつよう:leveraging:N3}しています。[韓国]{かんこく:Korean:N2}[向け]{むけ:for:N3}には[国内]{こくない:domestic:N3}[ISP]{あいえすぴー:ISP}との[ピアリング]{ぴありんぐ:peering}が[強化]{きょうか:strengthened:N3}されたエッジを、[中国]{ちゅうごく:China:N5}[本土]{ほんど:mainland:N5}[向け]{むけ:for:N3}には[現地]{げんち:local:N3}の[法的]{ほうてき:legal:N3}[要件]{ようけん:requirements:N3}に[適合]{てきごう:conforming:N3}したパートナーCDNを[使い分ける]{つかいわける:use selectively:N4}など、[地域]{ちいき:regional:N2}[ごとの]{ごとの:per}[最適]{さいてき:optimal:N3}[経路]{けいろ:routing:N3}を[実現]{じつげん:realize:N3}しています。\n\n#en\npixiv enjoys strong popularity in Asian regions including Korea, Taiwan, and China, leveraging CDN edges optimized for each region. For Korean users, edges with strengthened peering with domestic ISPs are used; for mainland China, partner CDNs that comply with local legal requirements are used. By selectively applying these, pixiv achieves optimal regional routing.\n::\n\n::heading\n[今後]{こんご:going forward:N5}の[展望]{てんぼう:outlook:N1}\n\n#en\nFuture Outlook\n::\n\n::para\npixivは[今後]{こんご:going forward:N5}、[動画]{どうがう:video:N4}[作品]{さくひん:works:N4}や[3D]{さんでぃー:3D}モデルなど[画像]{がぞう:image:N2}[以外]{いがい:beyond:N4}のメディアにも[配信]{はいしん:delivery:N3}[基盤]{きばん:platform:N1}を[拡張]{かくちょう:extend:N1}する[計画]{けいかく:plan:N4}です。また、[生成]{せいせい:generative:N3}AIによる[類似]{るいじ:similar:N3}[画像]{がぞう:image:N2}[検索]{けんさく:search:N1}や、エッジでの[著作権]{ちょさくけん:copyright:N2}[侵害]{しんがい:infringement:N1}[検知]{けんち:detection:N1}にも[取り組み]{とりくみ:work on:N3}、[クリエイター]{くりえいたー:creator}を[守り]{まもり:protect:N3}ながら[作品]{さくひん:works:N4}を[世界]{せかい:world:N4}に[届ける]{とどける:deliver:N2}[基盤]{きばん:platform:N1}を[目指して]{めざして:aiming for:N3}います。\n\n#en\nGoing forward, pixiv plans to extend its delivery platform beyond images to media such as video works and 3D models. The company is also working on similarity search powered by generative AI and on edge-based copyright-infringement detection, aiming for a platform that delivers works to the world while protecting creators.\n::\n",{"id":66,"title":69,"titleEn":70,"topicPath":10,"questions":71},"テック確認テスト — pixivの画像配信基盤","Tech Check — pixiv Image CDN",[72,96,119,143,166,190],{"id":73,"articleId":6,"question":74,"options":77,"correctLabel":85,"explanation":90,"tags":93},"tech-pixiv-image-cdn-quiz-q01",{"en":75,"jp":76},"In pixiv's image-delivery platform, which CDN vendor has been its partner for many years?","pixivの画像配信基盤において、長年にわたって提携しているCDN事業者はどこですか。",[78,81,84,87],{"label":79,"jp":80,"en":80},"ア","Akamai",{"label":82,"jp":83,"en":83},"イ","Cloudflare",{"label":85,"jp":86,"en":86},"ウ","Fastly",{"label":88,"jp":89,"en":89},"エ","AWS CloudFront",{"en":91,"jp":92},"The article explicitly states that pixiv has long partnered with the US-based CDN vendor Fastly, leveraging its flexible VCL-based control and instant cache purging.","本文では、pixivは長年にわたり米国のCDN事業者Fastlyと提携し、VCLによる柔軟な制御と即時キャッシュパージを活用していると明示されています。",[94,95],"cdn","fastly",{"id":97,"articleId":6,"question":98,"options":101,"correctLabel":82,"explanation":114,"tags":117},"tech-pixiv-image-cdn-quiz-q02",{"en":99,"jp":100},"Regarding the image formats pixiv offers, what is the main advantage of adopting AVIF?","pixivが提供する画像形式について、AVIFを採用する主な利点は何ですか。",[102,105,108,111],{"label":79,"jp":103,"en":104},"全ブラウザで標準対応しているから","It is supported by default in all browsers",{"label":82,"jp":106,"en":107},"同等画質でJPEGの半分以下の容量に収まるから","It fits into less than half the size of JPEG at equivalent quality",{"label":85,"jp":109,"en":110},"アニメーション機能が豊富だから","It has rich animation features",{"label":88,"jp":112,"en":113},"古い端末でも再生できるから","Even old devices can render it",{"en":115,"jp":116},"The article explains that AVIF fits equivalent visual quality into less than half the size of JPEG, significantly reducing transfer volume and load time.","本文ではAVIFは同等画質でJPEGの半分以下の容量に収まり、転送量と読み込み時間を大幅に削減できると説明されています。",[45,118],"avif",{"id":120,"articleId":6,"question":121,"options":124,"correctLabel":82,"explanation":137,"tags":140},"tech-pixiv-image-cdn-quiz-q03",{"en":122,"jp":123},"What is the edge-side strategy for age-restricted content such as R-18?","R-18などの年齢制限コンテンツに対するエッジ側の戦略はどれですか。",[125,128,131,134],{"label":79,"jp":126,"en":127},"全リクエストをオリジンへ転送して判定する","Forward all requests to origin for judgment",{"label":82,"jp":129,"en":130},"Cookieと認証トークンをエッジで検査し、未認証は即座に拒否する","Inspect cookies and auth tokens at the edge and immediately reject unauthenticated requests",{"label":85,"jp":132,"en":133},"全コンテンツに自動でモザイクをかける","Automatically apply mosaic to all content",{"label":88,"jp":135,"en":136},"海外ユーザーのみ配信を許可する","Allow delivery only to overseas users",{"en":138,"jp":139},"The article explicitly states that edge servers inspect cookies and auth tokens, forward only age-verified users to the origin, and reject unauthenticated requests immediately at the edge.","本文では、エッジサーバーがCookieと認証トークンを検査し、年齢確認済みユーザーのみオリジンへ転送、未認証リクエストはエッジで即座に拒否すると明示されています。",[141,142],"age-gate","security",{"id":144,"articleId":6,"question":145,"options":148,"correctLabel":82,"explanation":161,"tags":164},"tech-pixiv-image-cdn-quiz-q04",{"en":146,"jp":147},"Regarding the scale of pixiv's registered users and cumulative works, which numbers are stated in the article?","pixivの登録ユーザー数と累計作品数の規模について、本文で示されている数字はどれですか。",[149,152,155,158],{"label":79,"jp":150,"en":151},"登録ユーザー1000万人、作品500万点","10 million users, 5 million works",{"label":82,"jp":153,"en":154},"登録ユーザー7000万人、作品1億点超","70 million users, over 100 million works",{"label":85,"jp":156,"en":157},"登録ユーザー1億人、作品10億点超","100 million users, over 1 billion works",{"label":88,"jp":159,"en":160},"登録ユーザー300万人、作品1000万点","3 million users, 10 million works",{"en":162,"jp":163},"The article explicitly states that cumulative works exceed 100 million and registered users reach 70 million.","本文では、累計作品数が1億を超え、登録ユーザーは7000万に達していると明示されています。",[36,165],"numbers",{"id":167,"articleId":6,"question":168,"options":171,"correctLabel":82,"explanation":184,"tags":187},"tech-pixiv-image-cdn-quiz-q05",{"en":169,"jp":170},"Which is the most appropriate reason pixiv adopts on-the-fly resize?","pixivがオンザフライリサイズを採用している主な理由として最も適切なものはどれですか。",[172,175,178,181],{"label":79,"jp":173,"en":174},"アップロード時に全サイズを生成する方が速いから","Pre-generating all sizes at upload is faster",{"label":82,"jp":176,"en":177},"使われないサイズの生成コストを回避し、新解像度にも即対応できるから","To avoid the cost of generating unused sizes and to instantly support new resolutions",{"label":85,"jp":179,"en":180},"オリジナル画像を保存しないため","Because they do not store the original image",{"label":88,"jp":182,"en":183},"CDNがリサイズを必須としているから","Because the CDN requires resizing",{"en":185,"jp":186},"The article explains that by encoding the size in the URL and resizing at the edge on first request, pixiv avoids the cost of generating unused sizes and can instantly support new device resolutions.","本文では、URLにサイズ指定を含めエッジで初回リサイズしてキャッシュすることで、使われないサイズの生成コストを回避し、新しい端末解像度にも即座に対応できると説明されています。",[188,189],"resize","edge-compute",{"id":191,"articleId":6,"question":192,"options":195,"correctLabel":82,"explanation":208,"tags":211},"tech-pixiv-image-cdn-quiz-q06",{"en":193,"jp":194},"Regarding overseas expansion, which approach is explicitly stated in the article for mainland China?","海外展開において、中国本土向けに採用されている方針として本文に明示されているものはどれですか。",[196,199,202,205],{"label":79,"jp":197,"en":198},"Fastlyのエッジを直接利用する","Use Fastly edges directly",{"label":82,"jp":200,"en":201},"現地の法的要件に適合したパートナーCDNを使い分ける","Selectively use partner CDNs that comply with local legal requirements",{"label":85,"jp":203,"en":204},"中国本土ではサービスを停止している","The service is suspended in mainland China",{"label":88,"jp":206,"en":207},"日本国内のサーバーから直接配信する","Deliver directly from servers in Japan",{"en":209,"jp":210},"The article explicitly states that for mainland China, partner CDNs compliant with local legal requirements are used selectively to realize optimal regional routing.","本文では、中国本土向けには現地の法的要件に適合したパートナーCDNを使い分け、地域ごとの最適経路を実現していると明示されています。",[212,213],"overseas","china"]