Meet Hummingbird!

Hummingbird helps keep your site running fast and efficiently. In this guide, we’ll cover all of the great features available for Hummingbird. With a few simple steps, you can find the weak points in your site’s performance and develop a plan to improve. Let’s dig in!

New to WordPress? Our Installing Plugins guide will walk you through installing your first plugin. Or, if you’re a member of WPMU DEV, you can use the WPMU DEV Dashboard plugin to easily install new plugins directly to your WordPress site.

Once Hummingbird is installed, your first stop is the plugin’s dashboard, which you’ll find under Hummingbird in your WP Admin menu. You’ll see an overview screen of the tools we’re giving you to keep your site running like a champ; Performance Test, Asset Optimization, Caching, GZIP Compression, Image Optimization (with Smush Pro), Advanced Tools and Uptime Monitoring.

Hummingbird Dashboard

Quick Setup

Quick setup popup

When you first install Hummingbird and go to Hummingbird > Dashboard, you will see the Quick Setup popup. This popup allows you to easily run your first performance test. You can skip it with the “SKIP” button at top right corner. We will explain how you can run a performance test whenever you want in the next chapter. But if you want to quickly see your website performance you can run a performance test quickly with the big blue button.

Running performance test

If you click the “RUN PERFORMANCE TEST” button you will see the progress popup. When the test is finished, you will be redirected to the Dashboard page again, and this time you will see the Dashboard with results.

2.1 Performance Test

Link to chapter 1

When you go to Hummingbird > Performance Test page without running quick setup you will see the run performance test notification page.

First time performance test page

You can click the “TEST MY WEBSITE” button and wait until the Hummingbird finish the test. Or if you run Quick Setup for the first time on the Dashboard screen; you will get the same page, when you go to the Performance Test page:

Performance test results

At a glance, you’ll be able to see your current performance score & the date of your last performance test. Beneath that, you’ll notice different tabs for different performance sections like Score Metrics or Audits. Let’s check each tab one by one!

Score Metrics

Score metrics

For the Score Metrics tab, Hummingbird will provide you the basic information about how your website handles the request. If you are seeing all the items on this page green that means perfect. But even if you see some yellow or red items, don’t worry, Hummingbird will help you about fixing them.

If you click on the row of these items, the listing will expand and provide you with additional information about what Hummingbird found and how to fix it. Every item has three sections when you expand it; you can get a summary from the Overview section, it will show you the current status from the Status section and what Hummingbird recommends at the Recommendations section.

Performance test item expanded

For many of the recommendations that Hummingbird makes, it is able to make these improvements for you. But sometimes Hummingbird needs to call on other superheroes like Smush to do the heavy lifting.

Whatever the case, Hummingbird will provide you with detailed information on what is a possible area of concern, and what you can do to improve the performance of your site. Let’s check some of the items together.

Speed Index

Speed index represents how much time passed to generate the above the fold content. You can think like even very small improvements can improve this metric. For example, deferring offscreen images (lazy loading) can stop the loading images if visitor not seeing them. So images which are visible to the visitor will load faster. You can configure lazy loading with our Smush plugin Lazyload page. Also, optimizing images can help to improve this and Smush can help about it too.

Or you can move unnecessary Stylesheets (CSS files) or Javascript files from header to footer. With that move, that unnecessary files will start loading after your content and your content will load faster.

First Meaningful Paint and First Contentful Paint

First Meaningful Paint (FMP), calculate how much time primary content takes to become visible. The quicker primary content will allow your visitors to engage with page quicker too. Primary content can be different for different pages. For example, while primary content for the social media site is user posts, it can be a title and featured image for the blog site.

First Contentful Paint (FCP), calculate how much time it takes when the user clicks a link from another site (like a search engine) and wait until the first bit of content. It can be anything like a text or image, this is important because it will feel a user that page started to loading.

The previous recommendations also will improve your website FMP and FCP too. Also, proper caching for your website can boost these values.

Time to Interactive

Time to Interactive (TTI) represents the amount of time it takes for your page to become fully interactive. To become fully interactive, a useful amount of the content should be visible on the page and the page should respond to user interactions in 50ms.

Mainly the Javascript files can affect this metric. So be sure you remove or move to footer unnecessary Javascript files. Also, you can contact your developer to improve them.

First CPU Idle

This represents the time when most elements on your page can respond to user interactions such as clicking a button or typing text into an input field. This will feel your users that they can start interacting with the page.

The other items recommendations also can improve this item too.


Hummingbird audits

You will see suggestions about how to improve page load speed on the Audits tab. The tab is divided into Opportunities, Diagnostics and Passed Audits. You should focus on fixing all Red notices and improving as many Yellow ones as you can.

As before, expanding the items will give you a suggestion on how to solve it. Let’s check again some of them together.

Reduce Server Response Times


Historic Field Data

This section can show you anonymized real-world stats about how your website performs while visitors request a particular URL of your website. This report can be harder to create because it will track real users, so be patient and give time to see the results. This report is usually generated in 30 days.


You can schedule regular performance tests and get reports to your email from the Reports tab. Also, you can choose the desired device and result types while running the tests.


At the Settings tab, you can set some general options for the performance report. For example, you can customize the performance report Dashboard Widget or Hub Widget. Or you can ignore current results.

2.2 Caching

Link to chapter 2

When you click the “Caching” sub menu item under the Hummingbird you will be redirected to Page Caching settings page. It comes as deactivated by default and you can enable it from this page.

page caching deactivated

Page caching will save your pages as HTML, and when your visitors try to access them they will load faster.

page caching active

Note: If you update your page and can’t see the changes on the frontend, press the “Clear cache” button in order to load up your new resources.

Below the title, you will see Page Types options. You can select specific page types to cache or not. Also, if you are developing your own page templates you can use “define(‘DONOTCACHEPAGE’, true);” PHP code to prevent that page template from caching.

page caching general settings

After the Page Types, you can see some general settings about page caching. All of these settings are turned off by default, and you can activate them by clicking the gray slide icon. Once they are activated icon will color as blue.

page caching exclusions

Below the general settings, you can see the Exclusions settings.

URL Strings will let you specify exact URLs to prevent from caching. URLs are added one per line and you can use regular expression syntax. We already added a few for you by default, like sitemap.xml.

User Agents is used for preventing caching based on the user agent. It’s helpful to prevent caching for search engines to provide them always live data. Also in this section, we already added some useful settings for you!

Lastly, on this page, you will see the “Deactivate” button. You can use it if you ever want to deactivate page caching completely.

Browser Caching

browser caching

Browser caching stores temporary data on your visitors’ devices so that they won’t download assets twice if they don’t have to. This results in a much faster second time around page load speed. Enabling caching will set the recommended expiry times for your content.

To enable Browser Caching, scroll a bit further down the page to see the various options available for configuration.

configure browser caching

Expiry Settings  – Here you can decide how long you would like to keep your cache stored before it’s reset. By default, 8 days is selected, but you can increase or decrease this as needed. If you have a static site that does not change much, you could set this for a much longer period of time.

You can also choose to configure different expiry settings based on the cache type (javascript, CSS, media, images).

enable browser cache

Setup – In this section, if Hummingbird can edit your server configuration file, you can click the AUTOMATIC tab and activate Hummingbird browser caching. Hummingbird will handle everything for you.

But if your server doesn’t allow to edit the server configuration or any problem with automatic workflow, you need to click MANUAL tab and follow the instructions on there.

PRO TIP – Don’t sweat it if this seems a little out of your depth – just open a support chat and our experts will help you out. :)

Special Note About Cloudflare

If you are using Cloudflare for your CDN, then Hummingbird makes it easy for you to connect your Cloudflare account.

Why would you do this, you may ask? Because if Hummingbird does not manage your Cloudflare connection, then you risk Cloudflare overwriting changes you make in Hummingbird.

If you don’t have Cloudflare yet, you can signup here. And if you’re interested in learning more about the benefits of using a CDN, head on over to our blog.

Gravatar Caching

gravatar caching

Gravatar caching allows you to store local copies of avatars used in comments and in your theme. You can control how often you want the cache purged depending on how your website is set up. This is a great option to enable if you have an active blog or community!

Just click on Activate and you’re all set. Simple as that.

gravatar active

From here, you can choose to clear the cache when needed or deactivate Gravatar Caching altogether.

RSS Caching

rss caching

RSS Caching is handling by WordPress itself and activated by default. But Hummingbird gives you control over it. You can change Expiry time or you can disable RSS caching.


Settings module allows you to make even the smallest adjustments for your own convenience.

Admin Cache Control

Admin cache control

Admin cache controls allow you to put a button on top of your WordPress Dashboard so you don’t have to come in this area every time you want to clear the cache. Once activate this option, you will get a “Clear page cache” button on top of your WordPress Dashboard (note: after you Save you need to refresh your pages as well, for the new button to appear):

Clear page cache

Pretty neat, right?

File Change Detection

File change detection

Manual notice will give a global notice inside your WordPress Admin area, Automatic will clear cache automatically for you or you can totally disable File Change Detection by selecting None.

2.3 Gzip Compression

Link to chapter 3

Next up is Gzip compression! Gzip compresses your webpages and style sheets before sending them over to the browser, which makes for faster loading times.

gzip widget

From the Hummingbird Dashboard, you can click on the Configure button to be taken to the Gzip section.

Based on your server configuration you may notice that a few of the Gzip features are already enabled on your website. To configure the rest, just select your server type from the drop-down menu on the configure widget.

gzip configure

For Apache servers, enabling Gzip Compression is as easy as one click of the mouse.

gzip activated

Voila! Gzip Compression is all set up. Super easy, right?

2.4 Asset Optimization

Link to chapter 4

Asset Optimization is probably one of the most powerful features within Hummingbird.

If you are on a Single WordPress installation go to Hummingbird/Asset Optimization and click Activate to begin or, if you are on a Multisite, go to Network Admin/Hummingbird/Dashboard and setup your desired options.

asset optimization in multisite

Asset Optimization on Multisite is done on a per-site basis. This means that each subsite (including your main site) would need to have a separate Asset Optimization setup. This is not something you would always want for your subsites administrators to have (since it can break the Front End of their subsite) so you can choose who can make these adjustments or you can disable it completely.

The administrators of Subsites on your network will have a link guiding them to this manual, but if you want to grab their attention and leave additional notes, regarding Asset Optimization or anything else for that matter, check out Branda.

activate asset optimization

Let’s begin – click on Activate in order to scan and optimize your files!

If you have the Pro version, during the checkup process, you’ll be able to choose to store/host your stylesheet files (.css) and Javascript (.js) files on our CDN. Take note that this is all done in the background via CRON task (so it does not slow your site in the process) and will take some time to finish, so just give it a few moments and then refresh your main page :)

By default, we minify your files via our API and then send them back to your server. With this setting enabled we will host your files on WPMU DEV’s secure and hyper-fast CDN (only available on the Pro version) which will mean less load on your server and fast visitor experience.

Should you use a CDN for your WebSite? We think that you should, as it will give your website an even better performance, but if you have any doubts or you want to learn more about CDN take a quick look here.

If you wish you can skip this option for now but don’t worry as you can always enable/disable it later from Hummingbird/Asset Optimization.

asset optimization result

In this example, Hummingbird was able to reduce my files by 13.9%. You can also see that 32 files were identified. Note that the PRO version gives you access to Super-compression (this is automatically enabled within the PRO version) so you can get even more savings/compression by upgrading your plugin.


Asset optimization engine will list all the files it was able to locate and each file will have its own status. You will encounter these statuses:

file status

Gray compress icon – marks the files that are already compressed (like *.min.js and *.min.css.). Compress option will be grayed out here as those files are already minified

White compress icon – marks the files that can be compressed. The left side of those files, you will see that they are still compressing…

compressing files

In order to trigger Compression of your files (and the Cron job that does this) just refresh the Main Page of your site from the Front End and then refresh the Asset Optimization page from the Back End. Results will be something like:

compressed files

Can’t be compressed – marks the files that can’t be compressed (usually it’s external resources).

Make sure to always check file status so you can see what is happening or does it need an extra action :)

Advanced mode

If you wish to delve deeper into Asset Optimization and further optimize the speed and loading time of your site click on the Advanced mode.

advanced switch button

Before you start please get familiar with the basic guidelines given here.

The most important thing when working with Advanced mode and making changes to how your site loads files is that you test things out after every single change.

It is not recommended to select all your files, click on Bulk Update, and enable all of the options at once. This could have disastrous consequences for your site, and break a lot of things! Please do not do this!

You won’t be able to apply every option to every file, so it is very important to test as you go. (and make sure to click on Publish Changes beforehand!)

If a change you make does not work or affects the Front End of your site, then just go back to the Asset Optimization section and undo the last change you made. After you save your changes again and clear your cache, everything will be right back as it was before.

This process can take some time to get right, but once you do it will be worth it! Remember if you get stuck or have any questions, our support team is always available to help you out.

Let’s explain the available options first.

advanced mode

Compress – Compression removes the clutter from CSS and Javascript files. Smaller files, in turn, help your site load faster, since your server doesn’t have to waste time reading unnecessary characters & spaces.

Combine – Whenever possible, Hummingbird can combine smaller files together to reduce the number of requests made when a page is loaded. Less requests mean less waiting, and faster page speeds!

Asset Optimization engine is built in a way to respect WordPress dependencies for styles and scripts. That means that two or more files will be combined only when they have identical attributes otherwise they will be skipped. For example, if you choose to combine file 1, 2, 3 and 4, Asset Optimization engine will first try to combine file 1 and 2 and if that fails (due to dependencies described above) it will then try to combine file 2 and 3 and so forth.

If your Asset Optimization page does not contain the Combine option this means that the Combine option is disabled because your server has HTTP/2 activated. HTTP/2 automatically optimizes the delivery of assets for you

Move to Footer – When it comes to rendering blocking issues and WordPress, the best practice is to load as many scripts as possible in the footer of your site, so slow-loading scripts won’t prevent vital parts of your site from loading quickly. For each file and every file, you will be able to decide whether you want to move them to the footer or leave them in their original position. You can read more on render blocking and positioning here.

Inline CSS – To add CSS styles to your website, you can use three different ways to insert the CSS. You can Use an “External Stylesheet”, an “Internal Stylesheet”, or in “Inline Style”. The inline style uses the HTML “style” attribute. This allows CSS properties on a “per tag” basis.

Defer (Force load this file after the page has loaded) – For JavaScript (JS) files you will have the option to Defer it (force load it after the page had loaded). This means they will load only after everything else on your page has loaded, which allows you to load the most important files & content first.

Don’t load file – If you click this, it will prevent the file while loading page.

Right above the list of files, you’ll see two more options:

Bulk Update – if you know you have multiple files that need to have a single action applied to them, you can click the checkbox next to each file and then click on the “Bulk Update” button. A screen will then pop up that will let you choose which options to apply to all of the selected files.

Note that you can not Defer a CSS or set Inline for Javascript.

Filter – Looking for something specific? No worries! Just click on Filter, and you’ll be able to view/sort files from a specific plugin or theme, or even search the file you want to optimize by name.

You can also see two buttons in the top right of this section:

Re-check Files – this option allows for you to have Hummingbird scan your site again to check for any new files while preserving current setting. For example, this is handy if you installed (or uninstalled) a plugin and are not seeing the files added to the list here.

Clear cache – this option clears all local or hosted assets and re-compresses files that need it.


If you want to load all your CSS files at the footer but you have some critical CSS codes that need to load in <head>, you can use Tools tab. You will find textarea for your CSS codes, you just need to enter codes and click SAVE CHANGES button.


Under Asset Optimization/Settings you can:

File Location – By default, Hummingbird will keep your modified assets at /wp-content/uploads/hummingbird-assets folder. If you want to change that you can use this setting.

Super-compress my files – Compress your files up to 2x more than regular optimization and reduce your page load speed even further. This is Auto Enabled on the Pro Version and is not available on the FREE version

Enable WPMU DEV CDN – By default your files are hosted on your own server. With this setting enabled we will host your files on WPMU DEV’s secure and hyper fast CDN. Only available on the Pro Version. You can choose to activate/deactivate it here. This is only available on a Single site installation, on Multisite CDN is controlled via the Network Admin settings for all the subsites.

Debug – If you experience any issue with Asset Optimization, you can enable debug option to get more information about the process.

Reset to defaults – If your frontend has fallen apart or you just want to go back to the default settings you can use this button to do so. It will clear all your settings and run a new file check.

Deactivate – you can completely turn off Asset Optimization here.

2.5 Image Optimization - with Smush

Link to chapter 5

Once you’ve run your first Hummingbird scan, you may find that some of your images need to be optimized.

image optimization need

Your Hummingbird results will tell you if these images just need to be compressed, or if compressing and resizing is necessary.

For resizing, you can turn to the WordPress image editor to crop and scale those images to match the embedded size in your content.

For compressing, Hummingbird enlists the help of Smush. You can find Smush in the WordPress repository if you are not a member of WPMU DEV. Or you can install Smush Pro from the WPMU DEV Dashboard.

install smush

If you already have Smush installed & activated, you will see an Image Optimization module on the Hummingbird Dashboard that gives you a quick overview if you have any images that need to be optimized.

image optimization

Additional Information

After you activated Smush, head over here to read our usage guide to learn how to use Smush. And then to our blog for additional information about image optimization, and how to get the most from Smush Pro.


2.6 Advanced Tools

Link to chapter 6


2.7 Uptime

Link to chapter 7

Uptime Monitoring is one of the awesome perks exclusive to WPMU DEV members.


These features allow for you to set up email notifications alerting you immediately if your website goes down, and also letting you know when your website has come back up. You can also keep track of some helpful statistics that help you keep track of how long your site was down for, when the last time your site went down, as well as your server response times.

To get started, make sure you have the WPMU DEV Dashboard installed & activated on your site – and ensure that you are logged into the Dashboard with an active WPMU DEV membership. (Uptime Monitoring will only work with an active membership.)

uptime widget

When you return to the Hummingbird Dashboard, you’ll see a blue Activate button in the Uptime module. Click on this button to be redirected to Uptime Monitoring section within Hummingbird.

uptime general

At the top of the Uptime section, you’ll see a lot of interesting information regarding your site. Since this is the first time you’ve turned on Uptime Monitoring, it’s possible that there isn’t much information to see.

Beneath this, you’ll find a nifty graph of the response time of your site at various times throughout the reporting period:

response times



Uptime monitoring pings your site every 2 minutes and if your site did not respond or your HomePage took more then 30 sec to load it will send you a notice. If, on the other hand, everything works and loads normally but you are still getting Uptime notices please check your Firewall and whitelist these 2 IPs:,

From the Downtime tab, you can see the report about your past downtimes and stats about them. It also will show you how much time your site was staying down.



You can configure email notification to get an email when your site down. When you activate the “Configure” option, it will show you recipients and threshold. You can get a notification instantly when your site down or up to 30 Minutes later.



Also, you can get reports to your email with Response Time and Downtime together. You just need to go Reports tab and enable it from the Configure option. You will get Recipients and Schedule options when you enable it.



If you no longer wish to use Hummingbird’s Uptime Monitor, from the settings tab, you can completely deactivate Uptime Monitor.

2.8 Settings

Link to chapter 8

You can set some general settings from the Hummingbird/Settings page.


On the Data & Settings, you can change the behavior of the plugin for data. You can choose to Preserve or Reset from the Settings part. It will only affect the plugin settings. You can choose to Keep or Remove data from the Data part. It will affect the data that the plugin collects based on your site.

Also, there is a Reset Settings button. If you want to reset all your settings immediately, you can use that button.


From the accessibility tab, you can enable High Contrast mode. After enabling this option, the plugin will increase the visibility and accessibility of elements and components to meet WCAG AAA requirements.

2.9 Additional Help

Link to chapter 9

Do you have any questions for us? Was something in this guide unclear? Please let us know!

You can open a live support chat anytime to get started talking to a member of our support team right away. We’re always here to help.

Hi, I’m available right now to answer any of your questions :)

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