When you’re visiting sites other than Gmail, it’s easy to find out how many unread messages are in your inbox by glancing at the title of your Gmail tab or window. However, if you have a ton of tabs open, or if you use Chrome’s “Pin Tab” feature that hides everything except the tab’s icon, it can be tricky to figure out without switching tabs.

If you’ve ever found yourself in this situation, you may like the new Unread message icon we just added to Gmail Labs. It embeds the number of unread messages you have right into the Gmail icon itself, like this:

To turn it on, go to the Labs tab in Settings, enable this lab, and click the “Save Changes” button at the very bottom of the page. Note that it’ll only works in Chrome (version 6 and above) and Firefox (version 2 and above).

Have you ever found it just a little bit tricky to find what you were looking for on the Gmail Labs Settings page? Scrolling was ok when there were a handful of Labs, but now that there are over 50 it’s another story. A lunchtime discussion made us realize that having to rely on the browser’s search function or endless scrolling makes it hard to find the Labs features you want. So another Gmail engineer named Manu and I decided take an afternoon and address this. The result is an addition to the Settings page which filters the visible Labs as you type.

You can also link directly to the search results (e.g. http://mail.google.com/mail#settings/labs/video) if you’d like.

If you subscribe to a lot of mailing lists and like to keep an empty inbox, muting (or preventing a conversation from re-entering your inbox) is an essential feature. We just made a few changes that should make muting even better.

First up is “Smart Mute,” a new Gmail Labs feature that helps solve the problem of conversations that just won’t die. You know the ones I’m talking about: those emails with 10+ people cc’d where everyone replies all, but you lost interest five emails ago. The current mute behavior doesn’t do well in these situations since the messages are addressed to you. You end up with muted messages in your inbox, and the only way to prevent these emails from coming back to your inbox has been to create a custom filter for a specific conversation.

If you enable “Smart Mute” from the Labs tab in Gmail Settings, muted conversations will only appear in your inbox if a new message in the conversation is addressed to you and no one else, or a new email in the conversation adds you to the “To” or “Cc” line. Once you enable Smart Mute, mute behavior will change across all versions of Gmail: web, mobile, Android, etc. Try it out and let us know what you think.

Since you’ll likely be muting more than ever, we also added easier ways to unmute muted conversations. Previously, the only way to unmute a conversation was to move it to your inbox — not super intuitive and useless if the conversation was already in your inbox. Now there are two new ways to unmute a conversation. The first is through an “Unmute” option in the “More actions” menu. You’ll see this when you view or select a muted conversation.

If you’re viewing a muted conversation, you’ll see the second new way to unmute: the “Muted” label next to the subject line now behaves just like all other labels. Clicking on the “X” will remove the Muted label and unmute the conversation.

Hopefully these changes will make it easier to mute and unmute conversations.

When we added emoticons in Gmail, you responded with a nice big smile , but then you asked for more. So we added hundreds more emoticons through Gmail Labs. “But alas!” you cried. “How can I ever keep up with so many different choices? I am overwhelmed by the sheer immensity of emotion , amusement , and cute animals that Gmail has to offer.” Well, don’t despair, fine purveyor of emoticons. There is now a solution: “Recently Used Emoji” in Gmail Labs, which keeps track of the ten most recent emoticons you’ve used, and saves them for easy access. To turn it on, just visit the Labs tab of Gmail Settings.

No more searching through dozens of cat faces for the one that says, “I miss you, but I’m still ambivalent about our weekend plans.” You can now triumph over the plethora of emoticons, and easily add a pile of emotion to any email that you choose — let us know how it goes.

Today, whenever you open an email in your Gmail inbox and then archive or delete it, you’re taken back to your inbox. Many of you have asked for the ability to instead go to the next conversation. Keyboard ninjas will already be familiar with the “]” and “[“ keyboard shortcuts for archiving and going to the next/previous conversation. For everyone else (and for people who frequently mute or delete conversations rather than archive them) we’re offering a new feature in Gmail Labs called “Auto-advance,” which automatically opens the next conversation after you archive/delete/mute the one you’re on.

To get started with “Auto-advance” go to the Labs tab in Settings, enable it, and click the “Save changes” button. By default, “Auto-advance” will advance to the previous (older) conversation in your inbox — perfect for people who read their newest mail first. If you usually read your oldest email first and would rather advance to the next (newer) conversation, you can change the direction from the General Settings tab.

Hopefully this will save you some time the next time you have to deal with a crowded inbox. Try it out and let us know what you think.

Labels are more flexible than folders because a given email can have several labels but can’t be in several folders at the same time. A highly requested feature for labels, though, comes from the world of folders: the ability to organize labels hierarchically.

If you think this might be useful to you, go to the Gmail Labs tab under Settings, look for “Nested Labels,” enable it and click “Save.” You’ll then need to name your label with slashes (/) to make it the child of another. For example, let’s say you wanted to create a simple hierarchy with a “Home” label, and inside it a “Family” and a “Vacation” label. Just create three labels with the following names:

Home
Home/Family
Home/Vacation

You can then create “Home/Family/Kids,” “Home/Pets,” etc., to get something like the screenshot on the left. If you had the parent label “Home” before you don’t have to create it from scratch.

You can create complex hierarchies of labels if that’s the way you like to organize your mail, and you can expand/collapse labels to save space. You’ll always be able to tell whether a given label contains unread messages in its collapsed child labels by looking at whether it’s bold or not.

Please note that this lab doesn’t play nicely with the “Hide Read Labels” lab. You might not get exactly what you expect if you have both labs enabled; for example, the collapse/expand icons won’t always appear when they should.

Another highly requested feature is the ability to preview messages to get a glimpse on what they contain and maybe take immediate action without opening them.

This is exactly what “Message Sneak Peek” does. After you turn it on, right-clicking on a line in your inbox shows a preview pane with the message in it.

You can also use keyboard shortcuts for a faster sneak-peeking flow (enable keyboard shortcuts in Settings first if you haven’t done so): hit ‘h’ to open a sneak peek card, then navigate with ‘j’ and ‘k,’ and dismiss the current card by pressing “Escape.” Messages you peak at will stay unread (or it wouldn’t really be a sneak peek, would it?).

Happy nesting and peeking!

As you can imagine, those of us on the Google Calendar team spend a lot of time thinking about scheduling. We regularly talk to people who schedule and reschedule a lot of meetings: administrative assistants. Talking to them, we understand just how much time they spend looking at schedules, investigating other people’s calendars, finding replacement conference rooms and rescheduling conflicts. And then some manager’s travel plans change and everything starts over again.

If you’re searching for something on the web, you don’t just start randomly visiting pages looking for relevant content, you use a search engine. So we decided to apply some of Google’s search experience to the problem of scheduling. We experimented with using ranking algorithms to return the most relevant meeting times based on specified criteria like attendees, schedule complexity, conference rooms, and time zones. Just like Google search ranks the web, our scheduling search algorithm returns a ranked set of the best candidate dates and times.

Today we’re launching the result of that experiment, a gadget called Smart Rescheduler, in Google Calendar Labs. Once you turn it on, just select an event you’d like to reschedule, then click “Find a new time…”:

You’ll see ranked list of possible times for your meeting. By investigating the calendars others have shared with you, Google Calendar can make some educated guesses about how easy it might be to reschedule a conflicting meeting and even find you a replacement conference room nearby. This process is 100% automated — no Google employees are doing any work behind the scenes. You can refine the results by marking people as optional, changing the meeting duration, ignoring certain conflicts, or specifying the earliest and latest times you’ll accept. The results will immediately update to reflect your new requirements.

This feature is still experimental, so we’d love your ideas and feedback. Of course, we can’t make meetings more interesting, but we can try to save you frustration leading up to them.

Today, we’re happy to announce three new features in Calendar Labs. To try them out, just go to the Labs tab under Calendar Settings.

1. Event flair by Dave Marmaros
Want a little airplane icon next to information about your upcoming flight? Or stars next to meetings with your boss? This experiment lets you choose from forty different icons and add one to each Calendar event. Even better, if you invite people to your events, they’ll be able to see the icon you added too. After you enable this feature, click on an event and look for the “Event flair” gadget to activate.

2. Gentle reminders by Sorin Mocanu
If you keep Google Calendar open all day long, you probably end up seeing quite a few reminders every day. Browser alerts are okay, but I tried to find a way for Calendar notifications to integrate smoothly with everything else.

Turn on “Gentle Reminders,” and when you get a notification, the title of your Calendar window or tab will start blinking and the event details will stay in Calendar.

If you’re using this lab in a supported browser (currently Google Chrome for Windows and Google Chrome beta for Linux), you’ll also have the option to get your reminders in the next generation of floating desktop notifications:

After you enable this feature, you can configure notification options on the Settings page.

3. Automatically declining events by Lucia Fedorova and Miguel García
Have you ever checked your calendar and noticed that someone scheduled a really important meeting during your vacation or at a time when you’re not available? Now there’s a way to automatically decline events when you’re not around. Turn on “Automatically declining events,” block off times when you’re unavailable, and event invitations during this period will get automatically declined.

My little sister recently setup her Gmail account to retrieve messages from her school address, so she can check all of her email accounts in one place. She no longer has to constantly log in to two email programs, and she likes using Gmail’s powerful interface for all her mail.

However, sometimes she knows an email has already been sent to her school address, and she just can’t wait for the next scheduled fetch to have it show up in her Gmail inbox. As any big brother would, I tried to solve this issue for her and millions of Gmail users.

Turn on “Refresh POP accounts” from the Labs tab under Settings, and the refresh link at the top of your inbox will not only update your inbox with your new Gmail messages, it will also fetch messages from any other accounts which you have set up.

Try it out, and let us know if you have any feedback.

We launched Gmail Labs over a year and a half ago as a playground where engineers can come up with new features and let your input help decide which are good ideas and which don’t quite work out. Any engineer at Google can come up with a feature, code it, and launch it quickly to tens of millions of users.

Labs started out with 13 features and quickly grew to 60, with even more on the way. We’ve received countless comments and kept an eye on our stats: some of these experimental features were adopted by millions and others trickled along with little usage. A couple have already graduated from Labs and we’ve already retired one: Tasks was the first to become a regular part of Gmail, Right-side Labels was retired when we updated the way labels work, and Offline Gmail graduated a couple months back. Today, true to the original intent of Gmail Labs, we’re graduating six more features and retiring five.

Graduating:

1. Search Autocomplete
2. Go To Label
3. Forgotten Attachment Detector
4. YouTube Previews
5. Custom Label Colors
6. Vacation Dates

Retiring:

1. Muzzle
2. Fixed Width Font
3. Email Addict
4. Location in Signature
5. Random Signature

These decisions were made based based mainly on usage, taking feature polish and your feedback into account. We’ve also tweaked some of the graduating features to improve them before making them default Gmail features. For example, we’ve combined Go To Label with Search Autocomplete, making it easier than ever for you to find what you’re looking for.

Search Autocomplete and Go To Label
Start typing in the Gmail search box (English only for now), and Gmail suggests terms that might help you find what you’re looking for — from contact names to labels and advanced search operators.

We’ve integrated Go To Label into this search box as well. If you have keyboard shortcuts turned on, type “g” then “l” and instead of getting the old “Go to label” pop-up, you’ll be in the search box with the “label:” operator filled in for you. Start typing the label you want to go to, and autocomplete will take it from there. All you have to do is hit enter. If you want to send your cursor to the blank search field, the keyboard shortcut “/” will do it.

Forgotten Attachment Detector
From time to time, we all forget to attach a file and sheepishly send another email with the forgotten attachment. To help save you from that embarrassment, Gmail looks for phrases in your email that suggest you meant to attach a file and alerts you if it looks like you forgot an attachment.

YouTube Previews
If you’re like me, your friends probably often email you links to YouTube videos. Instead of having to click on the link and wait for a new window to load before you can watch the video, Gmail now shows YouTube previews right below the message. All you have to do is click the play button and enjoy.

Custom Label Colors
Why settle for a restrictive palette when you can choose from over 4000 possible color combinations to help distinguish and organize your labels? Just click on “Add custom color” from the regular labels interface.

Vacation Dates
If you specify which dates you’ll be away in advance, you won’t have to remember to turn on the vacation responder when when you’re actually on vacation. Set your dates in advance, and let Gmail do the rest.

Retiring features is always a tough decision — we invest in building and maintaining them and we realize some of you are probably fans of some of Gmail’s lesser-used features. But Labs are experimental features, and from time to time they may break (that’s why there’s a quick way to disable them), or even disappear. Over the next few days, you’ll see Muzzle, Fixed Width Font, Email Addict, Location in Signature, and Random Signature stop working and disappear from the Labs tab.

We’ll keep working on new Labs to help make your Gmail experience even better, and we’ll continue to graduate successful features and retire the ones that don’t work out to make room for new ones. Thank you to all the engineers who have worked on Labs features — especially Bruce, Darick, Jon (the intern), Ibrahim, Chris, Keith, Chad, Michael, and Marco! Please continue to send us feedback and remember that you vote for your favorite Labs features by using them and leaving comments.