Is fix_reflows enabled by default?

No. fix_reflows is in the dangerous set, which no RewriteLevel enables, not even AllFilters. Enable it by name, for testing and measurement only.

How do I enable fix_reflows on Apache and nginx?

Add ModPagespeedEnableFilters fix_reflows on Apache or pagespeed EnableFilters fix_reflows; on nginx. On IIS, add pagespeed EnableFilters fix_reflows to pagespeed.config.

filter · HTML filters

Fix reflows (fix_reflows)

Category:: HTML
CoreFilters:: No
OptimizeForBandwidth:: No
Risk:: Dangerous set

Experimental fix for layout reflows caused by deferred JavaScript. In the dangerous set; not for production.

When to use it

In the dangerous set: no RewriteLevel enables it, not even AllFilters. It exists for testing and measurement, not for production traffic.
Risk rating on these docs: Dangerous.

Risks

The HTML filters page lists no specific risks for this filter. If a page misbehaves with it, DisableFilters fix_reflows turns it off for the scope you set it in.

Configuration

Enable it in the module configuration, at server, virtual-host or location scope:

Apache

ModPagespeedEnableFilters fix_reflows

nginx

pagespeed EnableFilters fix_reflows;

IIS (pagespeed.config)

pagespeed EnableFilters fix_reflows

Scoping, ForbidFilters and the thresholds filters read: Choosing filters .

Frequently asked questions

What does the fix_reflows filter do?: Experimental fix for layout reflows caused by deferred JavaScript. In the dangerous set; not for production.
Is fix_reflows enabled by default?: No. fix_reflows is in the dangerous set, which no RewriteLevel enables, not even AllFilters. Enable it by name, for testing and measurement only.
How do I enable fix_reflows on Apache and nginx?: Add ModPagespeedEnableFilters fix_reflows on Apache or pagespeed EnableFilters fix_reflows; on nginx. On IIS, add pagespeed EnableFilters fix_reflows to pagespeed.config.

add_base_tag — Add base tag
add_head — Add head
add_ids — Add IDs
add_instrumentation — Add instrumentation
collapse_whitespace — Collapse whitespace
combine_heads — Combine heads
compute_statistics — Compute HTML statistics
convert_meta_tags — Convert meta tags

This page is drawn from the fix_reflows entry on HTML filters. Every filter in one table: PageSpeed filters.