8

I sometimes post photos on my blog, like when I'm blogging about food. I've been shrinking the huge pictures my phone takes down to a size that fits more reasonably in a browser window -- my browser window, so far -- because I don't want my posts to require a huge window. Recently I've noticed that the platform I use (Dreamwidth) now has some degree of responsiveness; if I make a Chrome window smaller it scales the photos too, and my posts even look fine on a phone. This was not always the case, and is still not the case in Firefox for some reason. (I haven't tested additional browsers.)

That some sites and/or browsers do scaling suggests I could use higher-resolution pictures, but some browsers don't scale so I don't want things to be too huge. In addition, bandwidth might still be a concern; not everybody has fiber or a beefy data plan, after all. And on the proverbial third hand, there are now high-DPI displays on which the photos I'm using might be tiny (I don't have direct knowledge).

Putting all this together, what are current good practices for photo sizes on blog posts? Should I keep doing what I'm doing, which is to scale down the width to under 1000px (generally ~800px)? How do I trade off large high-res displays on the one hand and smaller displays with browsers that don't auto-scale on the other?

Note that I'm not talking about special photos where I might especially want high-res (like that gorgeous sunset photo taken on vacation or the like). In that case I'd make a higher-res version available behind a click, so it's opt-in. Nor am I asking about print publications where higher-res is important for production values. I'm asking about "ordinary" photos included in blog posts.

  • I was wondering when you were going to "enter" the contest. In quotes because, as you say, you're running the thing so it's not a real entry. – Cyn Mar 3 at 21:55
  • 2
    @Cyn yes, I was holding off to let the real entrants build up some steam first. – Monica Cellio Mar 3 at 21:56
2

I use the "medium" size in Wordpress, which is 500 px width and height proportional as required by the image. This fits across my entire column (depending on the monitor/window size/browser of course). That's a center column of content with menu columns on either side.

It's a bit bigger than many other sites use, but it works for me. I may change it if I change my Wordpress theme. What's best for the size of the picture depends on the theme or website layout.

As you've pointed out, another important issue is platform. Wordpress automatically scales graphics. I just checked my blog from my phone and the graphics are the appropriate size (though some get blurry when enlarged...even if they're still smaller than the crisp photos on my large desktop monitor).

In general it's better to use relative sizes and not absolute ones. This is true for font size as well. What's gorgeous and perfect on your setup is impossible to read on someone else's.

2

Any online image can be scaled to 100% of the width of the webpage, that means it will always fill the available width, regardless of the actual pixel size.

compression is more important than pixel size

Somewhat more important than pixel size is compression. TinyPNG, pngquant, ImageOptim, and other online services can drastically reduce the file size of a large image by selectively removing the possible colors, typically reducing it to ~25% of the original download. Depending on the image, this compression can look almost "lossless", much cleaner than the chunky squares of JPG. These tools will allow your online images to be much higher in resolution while having a lower memory footprint and faster download time.

What size, specifically

Screens become larger and more dense. If you want to future-proof your photos, or display them on a 4K television, or if you want users to zoom into detail, the resolution must be higher. Use the compression tools I linked above to reduce their file size while keeping the higher resolution.

As with Cyn's answer, Wordpress, Facebook, and other blogging software will resize your photos in the feed, allowing users to click to see the full resolution. Your blogging software, or its theme may be controlling this for you. There is no way to say 1 particular size is the best. It depends on the kind of information in the photo, your website design, and the user device which varies by country so it's worth checking.

All internet traffic is increasingly skewing to mobile devices

Although engagement (the time spent on the website) is still slightly higher on desktop, most people will find your website on their mobile device. See this breakdown of mobile screen size usage by country. 2 sizes are most popular: 750*1334, 1080*1920 (screens are oriented for portrait). At a distant 3rd place are "budget" screens at 720x1280 and the "retina"-like high-density screens that double that (1440*2560, 1440*2960). The high-density screens aren't for images, but to make text appear sharper.

  • 1
    Oh, so instead of trying to scale the image itself, use scaling in the img tag? I hadn't thought of that. (Also didn't know you could use percentages and not just pixels.) – Monica Cellio Mar 3 at 20:32
  • OK but you're wasting a lot of download bandwidth by sending a 10MP image and telling the browser to downsize it to 2MP or even less. The image should still be appropriately sized before being uploaded to the blog. – David Richerby Mar 3 at 23:01
  • @DavidRicherby, the OP said she already scales the image down to ~800 - 1000px width. 10MP would be 4x that. – wetcircuit Mar 4 at 3:55
  • @wetcircuit OK but this answer and the asker's response to it doesn't make clear that you need to do both: scale in the web page and before uploading. By not mentioning scaling before uploading (but mentioning other things before uploading, such as careful compression), it looks like you're saying to just use scaling at the client end and that leads to mobile users downloading huge images over slow connections and then throwing most of it away. – David Richerby Mar 4 at 10:12
2

Depends on your audience.
First, decide how much quality do you want to offer to your visitors (in terms of image quality/details).

Second, if you use google analytics, you can make a list of:

  • for desktop users, you can get an idea what is the most common screen resolution;
  • for the mobile, almost the same (but this is a little bit complicated, keeping in mind the device dpi);

Third, you can always make responsive layouts with CSS media-queries, and of course, load different resources based on the medium the user comes from (e.g. you can load smaller images for users that come from mobile devices);

The main idea is to serve different content, based on the user device. And, of course, optimize every image to a quality level that you want to offer. If you want to spend more money on technology, you can also consider serving your content from a CDN (Content Delivery Network).

1

A quick and easy reply would be to save your photos for with a 60% quality. You can do this in Photoshop.

I would suggest photos should be no wider than 600 pixels if possible. For most media, the smartphone is the traffic channel. Smartphones have an approx 320-pixel wide screen.

Also, think of your pictures like banners. They should engage the reader but still not be as big as no one can find the article which continues below.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.