HTTP CachingThe headers that control browser and CDN caching, and what each does.ComputingSent by the server; obeyed by browsers and CDNs.HeaderEffectCache-Control: max-age=nFresh for n secondsCache-Control: no-storeNever cache at allCache-Control: no-cacheCache, but revalidate before useCache-Control: immutableNever revalidate within max-ageETagA version tag; sent back as If-None-MatchLast-ModifiedA date; sent back as If-Modified-SinceVaryCache separately per named headerThe pattern: hashed filenames with max-age=31536000, immutable —plus a short-lived HTML document that points at them.HTTP Cachinglearnposters.com
HTTP Caching — printable computing wall chart from LearnPosters. Free vector PDF, US Letter and A4.

What’s on the HTTP Caching poster

A 7-row table: Header · Effect.

Sent by the server; obeyed by browsers and CDNs.

The pattern: hashed filenames with max-age=31536000, immutable — plus a short-lived HTML document that points at them.

Questions about the HTTP Caching poster

What’s on the HTTP Caching poster?
A 7-row table: Header · Effect. Sent by the server; obeyed by browsers and CDNs. Cache-Control: max-age=n — Fresh for n seconds; Cache-Control: no-store — Never cache at all; Cache-Control: no-cache — Cache, but revalidate before use; Cache-Control: immutable — Never revalidate within max-age; ETag — A version tag; sent back as If-None-Match; Last-Modified — A date; sent back as If-Modified-Since; Vary — Cache separately per named header. The pattern: hashed filenames with max-age=31536000, immutable — plus a short-lived HTML document that points at them.
Who is the HTTP Caching poster for?
HTTP Caching belongs to the Computing section rather than to a school year, because computing is not something one grade owns. Anyone learning systems can pin it up — a beginner, a student mid-course, or someone revising years later.
When should you use the HTTP Caching poster?
Version your asset filenames and cache them forever. Cache HTML for seconds, not hours. A wall chart earns its place by being glanceable from where the work is happening, so HTTP Caching belongs on the wall where that computing work actually happens, within glancing distance, rather than filed away.
What other posters go with HTTP Caching?
Caching, Concurrency & Parallelism and DNS sit alongside HTTP Caching in the Computing section. Printed together they make a wall rather than a single sheet, which is how a reference set actually gets used.CachingConcurrency & ParallelismDNS
Is the HTTP Caching poster free to download and print?
Yes. HTTP Caching downloads as a free PDF with no account, no email and no watermark, like everything else in the Computing section. Print as many copies as you like for a home, a classroom, a library or a tutoring group; reselling the file is the only thing the licence rules out.Read the licence
What size does the HTTP Caching poster print at?
HTTP Caching is a vector PDF laid out for US Letter, and prints on A4 with Fit to page — the same file, no separate download. Because every mark on it is drawn rather than photographed, it stays sharp enlarged to A3, A2 or A1 at a copy shop. Colour carries emphasis only, so a greyscale print of HTTP Caching loses nothing.Printing guide

Related posters

Charts that sit alongside HTTP Caching on the same wall.

Browse every Computing poster, or start from the full catalogue.