#36 · Free CDN with Cloudflare

Ek line yaad rakho: copy paas rakho, server bachao.

Set it up (about 10 minutes)

1. Create a Cloudflare account → Add a site → enter your domain → choose the Free plan.
2. Cloudflare gives you two nameservers. At your domain registrar (GoDaddy, Namecheap, …) replace the old nameservers with these. The switch can take a few minutes to a few hours.
3. In the DNS tab, keep your record's cloud orange (Proxied). A grey cloud means DNS only, with no CDN.
4. Check it works:

curl -sI https://yoursite.com/logo.png | grep -i cf-cache-status
# first request:  cf-cache-status: MISS
# next request:   cf-cache-status: HIT   ← served from the CDN

By default Cloudflare caches static files such as images, CSS and JS, not HTML pages. Caching HTML needs separate Cache Rules. Check Cloudflare's site for the current free-plan limits.

How a CDN works inside

• The request goes to the edge server closest to the user.
• If the edge has a copy, that is a cache hit and the origin is never touched.
• If not, that is a cache miss: the edge fetches the file from the origin once, keeps it, and serves everyone after that from the copy.
• Result: a faster site, less load on your server and a smaller bandwidth bill.

Interview words

Follow-up questions

The file changed but the old copy is still cached. What now? Three options: keep the TTL short, purge the file on the CDN, or (best) change the file name, e.g. app.v2.css or app.3f9a.css. A new name means a new cache entry, so stale copies never matter. This is called cache busting.

Can you cache everything? No. Static files (images, CSS, JS, video) yes. User-specific data (cart, profile, balance) no, or one user's data can be shown to another.

What if every edge misses at the same time? The origin gets a sudden spike. An origin shield, a central cache layer between the edges and the origin, absorbs it so fewer requests reach the origin.