I’ve been receiving a few emails lately asking me for some of the web design resources that I personally use. Well, I’d like to start sharing my resources with our readers so today, I’ve gathered up a collection of the icon sets that I have personally downloaded and use on a daily basis.
One thing that I’ve emphasized before is to have a collection of resources at your disposal. There are a lot of different icons out there and choosing which ones to download and save in your resources can be difficult. I used to just be download happy and download every icon set that I found and I found that to be very ineffective as I would still end up having to sort through hundreds of folders looking for the right icons.
Well, in this post, I’d like to share some of my favorite icon sets that are available for download. And guess what, they are all free!

SPIRIT20

Spirit 20
This excellent icon set consists of almost 500 transparent PNGs at 20×20 pixels, and is   completely free to use for both personal and commercial projects. No   attribution is required.

ISLOO

Isloo
These fantastic icons are from Icon Finder. You can use them in any project you like. They were designed by the talented Asher   Abbasi. The freebie consists of 50 beautiful icons. The icons are all   colorful and detailed and can by used in any commercial project – just   don’t redistribute without written permission.

TOOLBAR ICON SET

Toolbar Icon Set
This free set comes with 35 icons that you can use in your website design. The icons are very detailed and looks great and it’s great to use especially if you want icons that aren’t too big or small.

BOOLEAN

Boolean
These icons are licensed under Creative Commons Attribution 3.0 license. The set took over one month to make. Now, Its all up to your creativity, the metaphors depicted here aren’t   meant to be used as is, you can give them your own spin, like the   Binocular for Search, Legos for Add-Ons/Plugins, Tree for directory   tree, what have you. If you want to use them without attribution in your commercial   works, then send an email to prax08@gmail.com

PIXELOPHILIA2

PixeloPhilia
A very nice icon set that I just recently found. The icons contained in this set are very useful and this set is a must-have for any web designer.

CORNER STONE

Cornerstone
This set from Iconlicious is just that, delicious. Although there’s not too many icons in this set, it’s still a very useful collection.

ICON SWEETS

Icon Sweets
IconSweets is a free icon set containing 60 vector Photoshop shapes, influenced by icon sets such as Glyphish and Pictoico. You may use these icons for both commercial and non-commercial projects and customize them any way you like.

WOOFUNCTION

WooThemes Function
The WooFunction Icon Set includes 178 amazing web-related icons in a   sophisticated and glossy design style. All 178 icons are available as   32×32 pixel PNG files and they are indeed   pixel-perfect. If you have an in-depth look at the individual icons,   you’ll notice that a lot of time was spent paying attention to the   finer details, which means that this is a really classy icon set.

GENTLEFACE TOOLBAR ICONS

Toolbar Icons
These icons can be used for wireframes and software mockups creation,   websites and software applications toolbars and menus including iPhone   and iPod apps. You’ll find a set of 8 cursors and 236 icons in black and   white color versions. The icons include pagination arrows, ratings and   voting controls, social interaction symbols file system and text editor   actions. The entire set totals   244 original icons optimized for 16×16 pixel size and available in   16×16, 32×32 and 48×48 pixel sizes.

KOMODO MEDIA SOCIAL NETWORK ICONS

Social Media
These social media icons, created by Rogie King are just perfect. I can’t even name the number of times that I have used these icons in my web projects. Definitely something that will be extra helpful to any web designer.

DEFAULT ICON

Default Icon
Default Icon is a repository of free icons in their simplest form. It can be used even   on portable devices (iPhone, iPad, android compatible devices etc) with   minimum capabilites as the resolution is 1-bit and  fully customizable as there is an eps version present. Available   for download in .eps, .png, .gif formats, in black and white colors, in sizes 16×16, 24×24, 32×32, 48×48, 64×64,   128×128, 256×256.

PICTODECK

Pictodeck
Pictodeck is a set of over 700 pictograms in   vector format designed specifically for Keynote. That means you   can rescale them to any size you desire without any loss in quality.   All of the icons also support transparency.

GLYPHISH

Glyphish
This icon set was designed and carefully optimized for use on toolbars and tab bars in   iPhone & iPad apps, they’re also perfect for Android apps, websites,   t-shirts more.

ICONIC

Iconic
Iconic is a minimal set of icons   consisting of 120 marks in raster and vector formats — free for public use.

MINI ICON COLLECTION

Mini Icons
Here are 113 10×10 greyscale icons in .gif format to use in your next design. Perfect for those small areas where you need to use an icon.

SANSCONS

Bitcons and Sanscons
Sanscons was design specifically for you to use CSS with them.   Due to their transparent background, you can apply any color or   background image to them for a more custom fit. Styling the icons takes   only a basic understanding of CSS.

SWEETIE-BASEPACK

Sweetie
The Sweetie family is cute and clean. And free! This set has been around   for five years, but it’s still going strong. So far its been downloaded   over 50,000 times, and is seen all over the web on great projects like BuddyPressRock Paper Shotgun, and VLC.

CIRCULAR ICON SET

Circular
A themed collection of 100+ 16×16 icons in alpha PNG format. Circular is   free to use for whatever you like without attribution – the only thing   that the creators ask is that you don’t distribute them yourself!

LED ICON SET

LED Icon Set
The LED Icon   Set was designed for web designers/developers by Aleksandr   Kozmenko. These .png icons make a professionally looking icon set and it is totally free.

QUARTZ

Quartz Icon Pack
Quartz is an icon set that contains 90 simple and stylish icons. Dedicated to the blogoshpere, Quartz Icon Pack has   numerous types of icons: files, folders, charts, books, boxes, social   networking sites, email etc. All icons are free to use for personal and   commercial projects.

LULLACONS

Lullacons
These icons are made to work on any background and in any browser. (Note   the 32×32 large icons only work well on lighter backgrounds). They are   in 8-bit PNG format, with 1-bit transparency. Worry not about IE   compatibility, which has full support for 1-bit transparency in PNGs.   IE/Win only does not support alpha-transparency in 24-bit PNGs (but will   be supported in IE7). If that was over your head, don’t worry. Just   rest easy knowing that these icons work in any browser.

CHALKWORK HTML

Chalkwork HTML
Chalkwork HTML is a free set of HTML-themed icons. Featuring 31 graphical representations of common markup elements, this is a   completely free icon set available for personal and commercial projects   alike.

TWOTINY

TwoTiny
The twotiny icon set was created for us in websites and web applications. The set features many diferent icons with a few color variations.

SILK

Silk Icons
“Silk” is a smooth, free icon set, containing over 700 16-by-16 pixel icons in strokably-soft PNG format. Containing a large variety of icons, you’re sure to find something that tickles your fancy. And all for a low low price of $0.00. You can’t say fairer than that.

MINI ICONS

Mini Icons
Another free set offered by famfamfam, “Mini” is a set of 144 GIF icons available for free use for any purpose.

BONUS: ICONZA

http://www.iconza.com/
Here’s a very useful site. Iconza is a collection of free icons that   can be colored and reduced in size to your taste. If you are a happy   site or blog owner, you will be able to pick icons that will fit right   into your design.