Support » Plugin: YITH WooCommerce Wishlist » Conflict with SG Optimizer

  • Resolved richsadams


    I updated your great plugin to v3.0.20 a few days ago on a site I maintain without issue. The site is built on the Flatsome theme.

    Yesterday I updated the SG Optimizer plugin on the same site to their latest, v5.7.15 and immediately noticed a dramatic slowing of the site response time (TTFB from 285ms to 1.8s). GTmetrix performance dropped from “A”/93% to “D”/58% (structure remained the same, “A”/96%).

    After plugin A/B testing, disabling either of the two plugins resolves the issue.

    I reached out to Sitegound and they found that the SG Optimizer’s Dynamic cache stops working properly when the Yith Woocommerce Wishlist plugin is active now. They noted that if a plugin, like YITH WooCommerce Wishlist, sets/uses cookies, that their caching mechanism would not work as they do not cache content with cookies as it could result in a number of difficulties such as mixed sessions, content not being updated, and other issues.

    I’ve deactivated the Yith Woocommerce Wishlist plugin for the time being to preserve the site’s performance.

    Are you able to review this? Would you suggest any server-side changes, and if so, which ones in particular?


    • This topic was modified 7 months, 3 weeks ago by richsadams. Reason: Typo
    • This topic was modified 7 months, 3 weeks ago by richsadams.
    • This topic was modified 7 months, 3 weeks ago by richsadams. Reason: Additional info
Viewing 7 replies - 1 through 7 (of 7 total)
  • Selah


    Can confirm that I am also facing the exact same issue on my website. Pages weren’t being cached using the Dynamic Caching feature on SG Optimizer and after disabling the “Yith WooCommerce Wishlist” plugin and another plugin “WooCommerce Multi Currency by Villa Theme”, the caching started working as intended again. After reaching out to SiteGround’s support, this is what they said:

    It looks like something on your site is initiating a session on the home page. Thus, our plugin does not cache the data to avoid possible security issues such as viewing the private session information of a different visitor due to cache. You may want to review the settings of your scripts and plugins and to consult the developers of the software you are using for this purpose (most likely the various Woocommerce plugins). They may be able to advise on how to avoid creating such sessions in a way which is incompatible with dynamic cache.

    Apart from this, after disabling the YITH WooCommerce plugin, I tested my website on GTMetrix and the loading speed improved by ~3 seconds.. Which is a big improvement in my opinion, from just disabling one plugin. Page loads in under 4 seconds now.

    • This reply was modified 7 months, 3 weeks ago by Selah.
    Plugin Author YITHEMES


    Hi there

    First of all, thank you for your report

    I’m not sure why this is happening just now, since session system has been the same since version 3.x of wishlist
    My best guess is that something suddnely changed with their algorythm, and as such it is difficult to prevent this kind of problems in the future

    Session cookie is registered in order to store unique ID for current guest user; that ID is then required in order to identify wishlists that are related to current session
    As you can see, in order to keep wishlist functional for guest users, there is little that we can do but create a cookie

    What we can do to help you prevent performance issues, is to review plugin code, and postpone cookie creation till the very moment user requests to add something to wishlist
    I’ll do some testing and update you on this thread about my conclusions

    Plugin Author YITHEMES


    Hi again

    I performed some testing on the plugin, and I found out that the very fact of checking if a product is in wishlist, was creating a new session for the guest users
    Given that session requires a dedicated cookie, this prevented cache from applying to any page, creating performance issues for any non-logged user

    For this reason I reviewed the plugin code, and prevented session creation, at least until user doesn’t interact directly with the wishlist (adds a product to the list)

    We’re still performing tests over these changes, but if everything goes as expected, next minor version will contain this patch
    I’ll keep you posted on updates



    Though I am not the one that started the thread, thanks for the update on this.

    Thread Starter richsadams


    Also my thanks @yithemes!

    Plugin Support Antonio La Rocca


    Hi guys

    Just a quick update on this topic; version 3.0.21 is now out with a fix to the problem that you reported

    Fix: avoid setting session_id, until guest performs any edit operation over the lists

    Thanks again for letting us know

    Thread Starter richsadams


    Thanks very much!

Viewing 7 replies - 1 through 7 (of 7 total)
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