Which is better for web design, Illustrator or Photoshop?

Photoshop

Adobe Ilustrator

Photoshop is the best for the web designing.because a graphical work  can be done easly  in photoshop and we can easly calculate the pixel size.

Launched in1988, Photoshop has become the one and only program for many designers today. It was originally created as a tool for photographers to edit and manage their photos - and for many people, this remains its primary use. However, due to the vast array of tools available, Photoshop is now so much more than this.

Illustrator started its life a little earlier than Photoshop in1987 and was primarily created for the typesetting and logo areas of graphic design. Illustrator is now seen as a tool for both graphic designers and digital artists to create many different types of digital products.

Well to answer which is better for web design?

For many designers (including myself) Photoshop is usually the first choice here for web graphics. As Photoshop graphics sit on a pixel based bitmap it would seem like the only choice for designing on screen media.

However, when designing user interfaces, Illustrator can provide many advantages that Photoshop cannot. Firstly, using Illustrator here makes the job a lot faster - there's the obvious resizing points. Illustrator is also great for creating reusable components. Using the symbols panel in Illustrator, you can create a library of icons and form elements that can be reused and manipulated many times over.

This not only speeds up your workflow but will also make your design more consistent. Also, as we're moving into a more responsive and agile web, we'll be seeing the need for resizable graphics more (ie. SVG & pixel fonts). If we're making considerations for our websites to be consistent across many different sizes, our websites’ graphics should surely follow suit. 

For the most part, Photoshop is still the winner here, but only just. I wouldn't rule Illustrator out completely. Quite often Illustrator is always a part of my workflow in designing UIs but most of the work is done in Photoshop.

the both is perfect for designing, it's all about the designer what did he prefer and having more experence

but the photoshop has one special option is the slice tool, It is perfect convert the design to html.

for me i would suggest the illustrator because it is a vector not like in photoshop it will be pixelated whenever the size is, if you aiming in an flat modern web design you should aim for the Illustrator.

i belive the photoshop is the best because the slicing tool is better for web optimization and the number one is Adobe Firework its give the smallest images with high-quality for web pages.

but as i always say, find your lovely software, and do your tasks, thats make you like the tasks as you can find a way to pass the difference with any another software.

photoshop is the best choise for web designing,

the best for webdesign is the illustrator program, it is mainly made for graphics where you can draw and create graphics designs. also its better for the pixels, where you choose the size you need, no matter how large or small it is, never pixelated. 

photoshop is for photo editing not more, the size you choose you can't make it large enough, otherwise it will be pixelated.

Illustrator but i think you might need Adobe Dreamweaver

For many web designers, adobe photoshop is the first choice, because it is pixel based, and therefore better on screen. 

Abobe Illustrator is better for graphic designers because it is vector based, and the material created can be resized without loss of quality.