Web Design Gurus

[Adam Randall]

I know the advantages of a png over a jpg or gif for editing eg transparency, however I see more and more web sites using png over the other two formats.

Would anyone like to comment on advantages or disadvantages of using png format on a web site?

[ray_223]

I don't think the use of JPG's has changed, they are still the best format for storing photograph type images.
GIF and PNG are better at storing "diagram" type images.

I know IE still has some problems with rendering transparent PNG's so I would have thought that GIF images would still be quite popular.

It seems like PNG's have some added advantages:
http://www.w3.org/QA/Tips/png-gif

[exstatic]

Ray hit the nail on the head, that w3c link should help you out.

PNG is a very flexible file format that will most likely start to overtake gif, it is patent free and is compatible with a huge range of applications.

There are however still some rendering issues with older browsers for PNG, such as issues with displaying transparency.

[Adam Randall]

Thanks very much for the info, I can rest easy knowing I dont have to redo all my icon images from png to gif and then relink them again.

[Heidi Price]

Hi Guys!

PNG is a high quality format that retains its "richness" when used within a website, so appearance-wise it is great.

The downside is that you need Fireworks to create it, but more importantly, quality has a price.

If you can absolutely guarantee your site visitors are running high speed broadband, go for it.

If your visitors are more likely to have 256 - 512 broadband (approx 70% in Australia) the image is gonna take a while to load.

And pity the poor dial-up users because they are going to see the image appear in strips about 20 pixels high and then recompile.

Yes, jpg can take a while too, which is why gif is so popular - it is the web-optimized standard, though not as high quality.

We actually maintain a dial-up connection so we can test load times, because there are many areas of Australia where the ONLY option is dial-up (grrrr Telstra and their crappy line infrastructure - personal bug-bear!).

Heidi

[No mans land]

GIF is licenced, PNG was a replacement.

Any software that uses the GIF compression format must pay a licence fee.

[Adam Randall]

Originally Posted by No mans land

GIF is licenced, PNG was a replacement.

Any software that uses the GIF compression format must pay a licence fee.

The cheque is in the mail

[David Tulloh]

Originally Posted by Heidi Price

Hi Guys!
...
The downside is that you need Fireworks to create it, but more importantly, quality has a price.

If you can absolutely guarantee your site visitors are running high speed broadband, go for it.
...

Many programs can create PNG images, including Photoshop, Gimp and even Microsoft Paint. I'd be surprised if there were many image programs that didn't support it.

On your second point, GIF only supports 256 colours. If you turn PNG down to only use 256 colours you will typically get a smaller image than GIF. There are tools to strip out the colour correction and other tables that can get the file size even smaller.

The main downside to PNG is that it was somewhat broken in IE6 and earlier. IE6 doesn't support gradual transparency in PNGs, so you get a jagged look. If this concerns you then force your images to only use full or no transparency. Again, GIF doesn't offer the partial transparency at all so you don't lose anything by this limitation.

I don't see any reason not to use PNG over GIF.

[ahortin]

Originally Posted by David Tulloh

The main downside to PNG is that it was somewhat broken in IE6 and earlier.

If only we could get rid of IE6, the world would be a far happier and better place!!

Anthony

[Astrid]

Just a quick note to jpgs, a bit off topic - the more often you re-save an image into jpg the more quality you loose as the software compresses the pic everytime you save.

So if you do any retouching or so better do it in the native format and save to jpg at the end.

Cheers
Astrid