Support » Plugin: Contact Form 7 » A GTMetrix Test: Is Google reCAPTCHA v3 Slower Than v2?

  • linux4me2


    When I read @eharris‘s post, I started wondering if Google reCAPTCHA v3 was actually slower and taking more resources than v2. I had looked at the GTmetrix score for one of my sites after seeing mention here that it was slower, and I didn’t see a significant difference, but I didn’t really look into it in detail. So I decided to do a little test.

    I started with a test site that I’d already updated to CF 7 5.1 with Google reCAPTCHA v3. I made sure both pages were cached, then ran GTMetrix three times (for an average) on both the Home and Contact pages. Then, I rolled back to v. 5.0.5 of CF 7, regenerated v2 reCAPTCHA keys, added back the [recaptcha] tag, made sure both pages were cached, and re-ran GTMetrix three times for each page. Here are the results:

    Home: 1.6s, 478kb, 46 requests
    Contact: 1.5s, 439kb, 46 requests

    Home: 1.0s, 238kb, 34 requests
    Contact: 1.4s, 416kb, 48 requests

    So, if that’s a valid test, the answer appears to be that Google reCAPTCHA v3 is significantly slower on non-contact-form pages and uses more resources on non-contact-form pages. V2 makes more requests on contact-form pages, but downloads less and is (maybe significantly) faster than v3.

    This was done on a dedicated server with 32 GB of RAM and a 1 G download port, so the speed differences might be more dramatic on a shared server or VPS with less RAM, though possibly not, because the scripts are being downloaded from Google’s servers.

    I was a proponent of Google reCAPTCHA v3. I truly hate that “I’m not a robot” checkbox because I always have to click on a bunch of pictures to get past it, but now I’m wondering if it wouldn’t be better to stick with v2. Google does say they’re going to keep supporting it…

Viewing 3 replies - 16 through 18 (of 18 total)
  • linux4me2


    I got curious about how the v2 reCAPTCHA would compare with just using some (hopefully) cleverly crafted quiz questions. here are the results:

    Google reCAPTCHA v2 Using CF 7 5.0.5
    Contact Page: 1.4s, 416kb, 48 requests

    Quiz Using CF 7 5.0.5
    Contact Page: 1.1s, 201kb, 34 requests

    Wow! I’ve got all my sites rolled back to CF 7 5.0.5 using Google reCAPTCHA v2, but I’m thinking about updating a couple of them and trying the quiz instead of Google’s reCAPTCHA.


    I just found this link:

    I’m not to bright with these techniques. I usually just install a plugin and it has to work. Now since I’ve been optimizing (and hired a firm to do so) my WP website to speed it up a bid, I yesterday noticed that is all of a sudden was slower after moving to recaptcha 3.

    Now, I understand the link I just shared could be a solution. However, I’ve no idea how to implement it. Since, like I’ve said, I normally just install a plugin and that’s it.

    Now my question is: Can the plugin solve this, or can somebody walk me through where to add all this code 😀

    Hi everybody,
    Your solution is the plugin “Gonzales”. I am not the developer behind it, just a user….happy user. This plugin allows you to decide which plugin to run on which page with single click. For example, I have set the js recaptcha script to run only on my contact page, but not on the other ones. Now my website uses recaptcha v3, but only on the selected page. You can check that here
    with this pugin you can significantly reduce the requests and loading time in general.
    Hope this info helps.
    Best Regards,

Viewing 3 replies - 16 through 18 (of 18 total)
  • The topic ‘A GTMetrix Test: Is Google reCAPTCHA v3 Slower Than v2?’ is closed to new replies.