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Sevalla can cache an application’s responses on Cloudflare’s network, so visitors get them from a location near them instead of from your application. The CDN caches static files such as images, scripts and stylesheets. Edge caching also caches rendered pages and every other response that’s safe to cache. Both are off by default, included at no extra cost, and work on every domain of the application, including its sevalla.app domain.

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How caching works

Every request to the application’s domains passes through Cloudflare. With the CDN or edge caching on, Cloudflare answers a GET request from its cache when it has a copy, and otherwise forwards it to your application and stores the response if it can.
Edge caching doesn’t look at request cookies. A page that changes per user (a dashboard, a cart, a signed-in view) is served from the cache to everyone unless its response sets a cookie or sends Cache-Control: private or no-store. Don’t turn on edge caching for highly dynamic applications without checking those headers.

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What is never cached

Sevalla always forwards these requests to your application, with or without caching:
  • Requests with a method other than GET, such as POST, PUT and DELETE.
  • Requests with an Authorization header.
  • Range requests (a Range header), for example for video seeking, and WebSocket upgrades.
  • Responses with a status other than 200, 301, 302 or 303.
  • Responses that set a cookie (Set-Cookie). For files with a cached extension, Sevalla first removes Cloudflare’s own __cf_bm bot-management cookie, so those files can still be cached.

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How long responses stay cached

If your response has a Cache-Control header, Sevalla leaves it as it is and Cloudflare follows it: no-store or private keeps the response out of the cache, and s-maxage or max-age sets how long it stays. If the response has no Cache-Control header, Sevalla adds one: For HTML pages, the added header lets Cloudflare keep the page for that time but tells browsers to check again on every visit (public, max-age=0, must-revalidate, s-maxage=<time>). Other files get the same time for browsers and Cloudflare (public, max-age=<time>, s-maxage=<time>). The cache key is the full URL, including the query string: /app.js?v=2 and /app.js?v=3 are cached separately.

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When the cache is cleared

Sevalla purges the cache of every domain of the application after every successful deployment, so visitors get the new version. You can also purge it yourself at any time. Cached copies of your files and pages are stored on Cloudflare’s network, outside the application’s location, for as long as they stay in the cache.

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Turn on the CDN or edge caching

1

Open the caching settings

In the sidebar, click Applications, then click the application. Click the Networking tab, then click Update settings in CDN & Edge caching.
2

Switch them on

Turn on CDN, Edge caching, or both. Each switch applies as soon as you flip it, without a deployment.
3

Close the sheet

Click Done.
The Update caching sheet with a CDN switch and an Edge caching switchThe Update caching sheet with a CDN switch and an Edge caching switch
The section then reads CDN is enabled and Edge caching is enabled. The application’s Overview tab shows the same status in its Cloudflare card. Cloudflare locations can take up to a minute to apply a change. To turn caching off, open the same sheet and turn the switches off. With both off, every request goes to your application. Copies cached before can be served again if you turn caching back on before they expire, so purge the cache when you turn it back on after changing content.

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Purge the cache

Purging removes every cached response of every domain of the application, for the CDN and edge caching together. The next requests go to your application and fill the cache again. On the application’s Networking tab, click Purge cache in CDN & Edge caching. There’s no confirmation: the dashboard shows Cache purged. when it’s done.

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Control caching from your application

  • Keep a response out of the cache: send Cache-Control: no-store or Cache-Control: private, or set a cookie in the response.
  • Cache a response for a set time: send Cache-Control: public, s-maxage=<seconds>. s-maxage applies to Cloudflare; max-age applies to browsers, and to Cloudflare when there’s no s-maxage.
  • Change a file without waiting for its cache to expire: give it a new URL (app.3f9c2.js or app.js?v=3), or purge the cache.
  • Bypass the cache for API calls: send them with an Authorization header, or use a method other than GET.

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Cached file extensions

With only the CDN on, Sevalla caches requests whose path ends in one of these extensions (matched without regard to case; the file’s content type doesn’t matter): 7z, afm, apk, avi, avif, bmp, bz2, cff, css, cur, data, dmg, doc, docx, eot, epub, exe, ffil, flac, flv, gif, gz, heic, heif, ico, img, iso, jfif, jpeg, jpg, js, json, lwfn, m4a, m4v, map, md, mid, midi, mkv, mov, mp3, mp4, mpga, odp, ods, odt, ogg, ogv, otf, pdf, pfb, pfm, png, ppt, pptx, pro, qt, rar, rtf, scss, std, svg, svgz, tar, tgz, tif, tiff, ttf, txt, wasm, wav, webm, webp, wmv, woff, woff2, xls, xlsx, xml, xsf, zip, zst. Edge caching doesn’t use this list: it caches every path.

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API and CLI

The toggle operations switch the current state: calling one twice turns the feature back off.