One of my webpages are about 23 kilobytes. Is this to much? Because I have seen webpages which are 174 kilobytes! How can these sites be so big but still have such a low load time?
Depends on alot of factors really. These days most people have high speed connections so the size of a page isn't really as important as it used to be. Webpages that have a huge filesize but load fast do so because they're more efficiently coded. The designs are probably CSS driven, images are optimized, database queries are streamlined or they might use caching, etc. In the end filesize is only a small factor in making sure pages load fast. It really depends on your hosting situation, traffic, and content.
So... If I use alot of PHP code on my page will that make my page slower? And do you have any hints on how to make one file make sitewide content changes? (this includes PHP, javascripts, html table layout, and images/content)
Really you should just do your best with presentation of your website, don't worry about the size. Use compressed images so atleast your size would be low but site would look good
whether it is okey or not if you can make it smaller then why not? the smaller it is the better, and the faster it will load for every one
As a rule of thumb I aim for 70k per 'page' as my desired size. If the graphics are going to make it larger than that, I say **** the graphics. Generally about 140k is the upper limit I would allow for anything I'm writing right now. I've seen pages lately pushing the envelope at a megabyte or larger lately and usually it's some art *** who can't accept the realities of the Internet meaning you might just have to have a bit of dithering and your smooth edges might not be pixel perfect if you want people to actually VISIT the page... But the thing most of these 'graphic artists' completely forget is people visit websites for the CONTENT, not the goofy graphics they drew in photoshop around the content. (or worse, shoehorned the content into after drawing their pretty picture). Get's even sadder when you see fat bloated flash elements that are by themselves as large or larger than what I consider the upper limit for an entire website... There's a reason people who build sites in flash are usually called flashtards... and why the only companies you see using that **** are the ones who's internet presence is an afterthought and could wipe their five year olds ass, put it online and call it a website and get away with it... See most of your fast food joints like McDonalds or Taco Bell for whom having a website is kind-of pointless and I'd be shocked if their visits were a quarter what they could be if they got rid of all that bandwidth wasting accessibility /FAIL/. With people still on metered connection plans, places like backwoods New Hampshire, Maine and the Rocky mountain states like Colorado being LUCKY if they can get a 56k connect that's not a long distance phone call, sizes remain as important today as they ever were; ESPECIALLY with devices like mobile phones and other handhelds often being on metered plans or throttled connection speeds. You also have to think in terms of server load - sure the end user might have 22mpbs broadband, but if your server is on a 100mbps connection and 100 people are accessing the site simultaneously, those users are only going to get 1mbps apiece. MODERN coding techniques can alleviate those bandwidth woes; separation of presentation from content moves a lot of the code into the EXTERNAL CSS, which ends up cached across pages making sub-pages of your site load faster using less bandwidth. Image-recombination techniques like 'sliding icons', 'css sprites', 'sliding doors' and 'eight corners under one roof' allow you to take multiple images and combine them down to single files, reducing the number of handshakes needed to the server and possibly reducing file sizes thanks to using a shared palette. Semantic markup and graceful degradation allow users with less capable connections to view a less graphics-heavy version of the page by simply turning images off in their browser, or even a non-layout version with CSS disabled... much less that semantics - using tags that say what things ARE NOT how they are going to appear can also help with your SEO. ... and just looking at you file sizes can often show you where your bottlenecks are - if you have a 50k HTML file and there's only 2-3k of CDATA in that HTML, you've probably royally screwed the pooch. I see that ALL the damned time.
I agree with deathshadow's accepted sizes (around 100kb or less). My sites (without images) are all around 10kb (HTML and CSS) though. I can't stand having to wait to load those 1mb beasts of pages on my phone, or with a slow WiFi connection. It's also the efficiency of the code (any commercial PHP system like phpBB or VBulletin are horrible in terms of efficiency), and amount of JavaScript that matters.
Less than 18% of internet users in the states are on dial up and those numbers are getting smaller everyday. It really depends on what kind of site you have and who your target audience is but generally today you'll find most of the biggest websites are not dial up friendly. I'd rather focus on giving 90% of my visitors a richer user experience and letting the dial up users wait a bit longer (like they're already used to for virtually every other website on the net). This seems to be a common mentality these days. As far as mobile devices, set up a redirect to a mobile-friendly version of your site (preferably one that can detect the device and style your website accordingly).
You also need to factor in if your web site is hosted with others or by it's self. If it's hosted on it's own server then it will definitely load a lot faster.