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 IBM Cloud CIS: Does aggressive edge caching interfere with HTML5 localStorage states?

Nauman Khan's profile image
Nauman Khan posted 07/08/26 02:57 PM

Hi everyone,

I am currently evaluating IBM Cloud Object Storage paired with Cloud Internet Services (CIS) to host a lightweight serverless web application, but I have a specific question regarding edge caching and client-side states.

I recently built a daily logic puzzle tailored for the Oceania region. You can inspect the lightweight DOM and JS structure at hang five nz.

The game operates entirely on client-side JavaScript—there is no backend database. The state machine relies strictly on the user's browser localStorage to save their daily streak and strict vowel-penalty status.

My question for the IBM Cloud architecture community: If I host this static JS/HTML bundle on IBM Cloud Object Storage and serve it via the CIS CDN, does the edge caching behavior ever force a hard refresh that could unexpectedly wipe or desync a user's localStorage session upon cache expiration?

I want to ensure users don't lose their puzzle progress when the edge cache TTL expires. Any insight into how CIS handles static HTML5 apps would be greatly appreciated!

Radwan Almsora's profile image
Radwan Almsora posted 07/09/26 03:38 PM

No, aggressive edge caching via IBM Cloud Internet Services (CIS) cannot interfere with, wipe, or desync HTML5 localStorage states.

localStorage is completely isolated within the user's physical web browser client and is strictly bound to the Same-Origin Policy (Protocol, Domain, and Port). Edge caching operates entirely on the network layer between the client and IBM Cloud Object Storage (COS); it does not possess the technical capability to clear or mutate data stored inside a user's browser sandboxed storage.

I belive this was answered here: 

How Edge functions work

Caching

Alex Steel's profile image
Alex Steel posted 08/04/26 07:41 AM

Aggressive edge caching usually doesn't interfere with HTML5 localStorage directly since localStorage stays in the browser. The more common issue is cached HTML or JavaScript serving outdated assets, which can create inconsistent application states. I've seen similar behavior while testing interactive web tools, and versioning static files together with selective cache rules helped keep everything consistent.😊