Time to First Byte

  • tonyzyc

    (@tonyzyc)


    4 days, 20 hours ago

    I’ve been using the OpenLiteSpeed server and LiteSpeed Cache for a week, and during this time I noticed a few issues:

    1. On PageSpeed Insights, the Time to First Byte (TTFB) increased from 0.8s to 1s, and Interaction to Next Paint (INP) also went up from 80ms to 87ms.
    2. Based on the time it takes me to open a single page, it feels noticeably slower than before; I previously used NGINX&Apache with WP Fast Cache.

    I used Presets->Advanced (Recommended) and didn’t make any other changes.

    I want to know the reason for the increase in TTFB and what changes I need to make to improve TTFB.

    Thank you!

Viewing 3 replies - 1 through 3 (of 3 total)
  • Plugin Support litetim

    (@litetim)

    3 days, 9 hours ago

    Hello @tonyzyc

    Most of that TTFB increase usually means your pages aren’t actually being served from cache — they’re falling through to PHP. A couple of things to check:

    1. Confirm caching is working. Run this twice (first load warms the cache):

    curl -I https://yoursite.com/

    Look at the x-litespeed-cache header. hit = served from cache (fast). miss every time = caching isn’t engaging. Make sure the cache module is loaded and a cache root is set in the OLS WebAdmin console from OpenLiteSpeed server. The plugin can’t cache anything if the server side isn’t configured.

    2. The difference in TTFB time is partly just noise. PSI’s lab test varies 100–300ms run to run. INP 80 → 87ms is nothing (anything under 200ms is “good”). Run PSI a few times and compare the average, not one result.

    3. One way to make sure the pages are always cached, turn on the LSC Crawler.

    4. Another way to improve with using a CDN. See QC CDN

    Start with #1 — confirming hit vs miss will almost certainly explain the slowdown. If it’s still missing after the OLS cache module/root is set up, post your response headers and someone can help further.

    • This reply was modified 3 days, 9 hours ago by litetim.
    • This reply was modified 3 days, 9 hours ago by litetim.
    Thread Starter tonyzyc

    (@tonyzyc)

    2 days, 15 hours ago

    I ran the curl command and got the following output. Please take a look and see if there’s a problem.
    HTTP/2 200
    content-type: text/html; charset=UTF-8
    expires: Thu, 19 Nov 1981 08:52:00 GMT
    cache-control: no-store, no-cache, must-revalidate
    pragma: no-cache
    x-dns-prefetch-control: on
    vary: Accept-Encoding
    server: cloudflare
    x-turbo-charged-by: LiteSpeed
    x-litespeed-cache: hit
    cf-cache-status: DYNAMIC

    Regarding “Make sure the cache module is loaded and a cache root is set in the OLS WebAdmin”

    Please provide detailed instructions on how to enable this feature.

    I tried enabling LiteSpeed Cache Crawler and filled out the sitemap.
    It doesn’t seem to be working.

    Crawler Cron Learn More
    Current sitemap crawl started at: 8m 57s ago
    The next complete sitemap crawl will start at: 06/19/2026 18:25:34
    Last complete run time for all crawlers: 372 seconds
    Current crawler started at: 2m 45s ago
    Current server load: 0.36
    Last interval: 2m 45s ago
    Ended reason: end

    Watch Crawler Status
    Start watching…
    Size: 0 Crawler: #1 Position: 1 Threads: 0 Status: end

    • This reply was modified 2 days, 15 hours ago by tonyzyc.
    Plugin Support litetim

    (@litetim)

    2 days, 14 hours ago

    @tonyzyc
    Ok, I need more info to help debug.
    Please send a report to Litespeed(from LSC module => Toolbox => click on Send to Litespeed).
    Then, please share the ID generated.

    Thank you

Viewing 3 replies - 1 through 3 (of 3 total)

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