mod_pagepseed full config with comments

.htaccess

<IfModule pagespeed_module>
    ModPagespeed On

    ModPagespeedRewriteLevel PassThrough
    #ModPagespeedEnableFilters convert_jpeg_to_webp,convert_jpeg_to_progressive

    # The 'Add Instrumentation' filter injects two small blocks of JavaScript into every HTML page. These blocks measure the time the client spends
    # loading and rendering the page, and report that measurement back to the server.
    # LOW RISK
    ModPagespeedEnableFilters add_instrumentation

    # The filter rewrites pages that load the Google Analytics tracking code synchronously to load it asynchronously instead. Loading Google Analytics
    # asynchronously has the advantage that it will not block resources that load later in the page.
    # LOW RISK
    ModPagespeedEnableFilters make_google_analytics_async

    # Uses CDN libraries if found a match
    # LOW RISK
    ModPagespeedEnableFilters canonicalize_javascript_libraries

    # Trims whitespace in HTML
    # LOW RISK
    ModPagespeedEnableFilters collapse_whitespace

    # Reduces CSS requests
    # LOW RISK
    ModPagespeedEnableFilters combine_css

    # Combines JS
    # LOW RISK
    ModPagespeedEnableFilters combine_javascript

    # defer_javascript tries to defer JavaScript execution until page load. It defers this by changing the type and src attributes of <script> elements
    # on the HTML page to pagespeed_orig_type and pagespeed_orig_src respectively. It also adds a new type attribute whose value is set to text/psajs. A
    # window.onload handler is added to the HTML, which executes all the deferred scripts.
    # HIGH RISK
    # ModPagespeedEnableFilters defer_javascript

    # The 'Elide Attributes' filter reduces the transfer size of HTML files by removing attributes from tags when the specified value is equal to the
    # default value for that attribute.
    # LOW RISK
    ModPagespeedEnableFilters elide_attributes

    # 'Extend Cache' seeks to improve the cacheability of a web page's resources without compromising the ability of site owners to change the resources
    # and have those changes propagate to users' browsers.
    # LOW RISK
    ModPagespeedEnableFilters extend_cache

    # Reduce the number of HTTP round-trips by combining multiple CSS resources into one.
    # LOW RISK
    ModPagespeedEnableFilters flatten_css_imports

    # The "Inline @import to Link" filter converts a <style> tag consisting of only @import statements into the corresponding <link> tags.
    # LOW RISK
    ModPagespeedEnableFilters inline_import_to_link

    #  The contents of small external CSS resources are written directly into the HTML document; therefore the browser does not request those CSS
    # resources independently.
    # LOW RISK
    ModPagespeedEnableFilters inline_css

    # The "Inline JavaScript" filter reduces the number of requests made by a web page by inserting the contents of small external JavaScript resources
    # directly into the HTML document.
    # LOW TO MODERATE RISK
    ModPagespeedEnableFilters inline_javascript

    # Generates low quality versions of the images that are inlined in the HTML page. Users experience faster rendering of the page and the low quality
    # images are replaced by high quality versions after an onload event is triggered. The filter works on images found in <img> tags.
    # MODERATE RISK
    ModPagespeedEnableFilters resize_mobile_images

    # The lazyload_images filter defers loading of images until they are visible in the client's viewport.
    # RISK: CPU cycles to calculate viewport
    ModPagespeedEnableFilters lazyload_images

    # This filter saves inlined resources to the browser's local storage (an HTML5 feature) on the first view of a page, and loads them from local
    # storage on subsequent views rather than sending them (inline) again.
    # MODERATE TO HIGH RISK, WONT SPEEDUP FIRST VIEWS
    ModPagespeedEnableFilters local_storage_cache

    # This filter minifies JavaScript code, using an algorithm similar to that in Douglas Crockford's popular JSMin program. At present, the filter
    # strips all comments and most whitespace. The filter works only on JavaScript found in <script> blocks (either as the target of the src attribute, # or within the body of the block).
    # LOW TO MODERATE RISK
    ModPagespeedEnableFilters rewrite_javascript

    #'Move CSS Above Scripts' seeks to make sure scripts do not block the loading of CSS resources.
    # LOW RISK
    ModPagespeedEnableFilters move_css_above_scripts

    # 'Move CSS to head' seeks to reduce the number of times the browser must re-flow the document by ensuring that the CSS styles are all parsed in the
    # head, before any body elements are introduced.
    # LOW RISK
    ModPagespeedEnableFilters move_css_to_head



    # Enabling convert_to_webp_lossless causes the image optimizer to attempt to create lossless webp images whenever it encounters gifs or pngs. The
    # lossless webp images are only served to modern browsers that support the format (libwebp version 0.2.0 and above).
    # LOW RISK
    ModPagespeedEnableFilters convert_to_webp_lossless

    # This flag inserts width= and height= attributes into <img> tags that lack them and sets them to the image's width and height. Note that this can
    # cause image stretching or shrinking if CSS rules specify only one image dimension
    # HIGH RISK
    ModPagespeedEnableFilters insert_image_dimensions


    # This is equivalent to enabling inline_images, recompress_images, convert_png_to_jpeg, and resize_images.
    # In every case, the image on the page is replaced by the optimized version only if the optimized version is actually smaller than the original.
    # MODERATE RISK, CPU cycles to resize or recompress
    ModPagespeedEnableFilters rewrite_images


    # Moves small JS to external resources
    # MAY NOT IMPROVE PERF AT ALL DEPENDING ON THE SITE
    ModPagespeedEnableFilters outline_javascript

    # DNS resolution time varies from <1ms for locally cached results, to hundreds of milliseconds due to the cascading nature of DNS. This can
    # contribute significantly towards total page load time. This filter reduces DNS lookup time by providing hints to the browser at the beginning of
    # the HTML, which allows the browser to pre-resolve DNS for resources on the page.
    # LOW RISK
    ModPagespeedEnableFilters insert_dns_prefetch

    # prioritize_critical_css parses the CSS and replaces it with inlined CSS that contains only the rules used on the page. This avoids any blocking
    # CSS requests needed for the initial render. It also collects all CSS tags and appends them to the HTML in the same order they were found. This
    # will make all style rules available after page load.
    # MODERATE RISK
    ModPagespeedEnableFilters prioritize_critical_css

    # Removes comments from HTML
    # MODERATE RISK
    ModPagespeedEnableFilters remove_comments

    # This filter parses linked and inline CSS, rewrites the images found and minifies the CSS. The filter works on CSS found in <style> blocks and <
    # link> refs.
    # MODERATE RISK
    ModPagespeedEnableFilters rewrite_css


    # The "Rewrite Style Attributes" filter rewrites the CSS inside elements' style attributes as performed by rewrite_css, which includes CSS
    # minification, image rewriting, image recompression, and cache extension, if enabled.
    # LOW RISK
    ModPagespeedEnableFilters rewrite_style_attributes

</IfModule>