How To Convert & Resize Images In Bulk

Ryan Dube 23-08-2012

If there is a single time-saving tip that I could ever offer to any writer, student, professional or anyone else that needs to produce documents with images, it’s the ability to bulk-resize images.


When I first started writing online, I would resize all of my web page images individually, depending on the page that I was writing for. Some websites required an image width of 450 pixels. Others wanted 500. Still others wanted 600. My digital camera takes photos that are typically around 1,200 pixels wide, and the images you get off image sites range from 300 pixels all the way upwards of over 1,000.

When you have 7 to 14 images per document you’re producing, through through all dozen or so pictures and performing a resize operation can be very tedious and a total waste of time.  Once I was entering into my third year of writing, I realized that the only way to succeed in this field is to streamline work. That meant, finding a much faster way to bulk resize images – a one-shot operation.

Thankfully, I found the perfect tool in irFanview. Here at MUO, we love IrFanview How to Edit Your Pictures for Free with IrfanView Plugins IrfanView is a free image viewer for Windows. With the right plugins, you can turn it into a powerful photo editor. We show you how you can use IrfanView to improve your photos. Read More . Tina write about some cool plugins for IrFanview 6 Cool IrfanView Plugins To Enhance This Simple Image Editor Read More , and I’ve written about how to use the command-line feature 10 Useful Command-Line IrfanView Tools For Working With Images These days, screenshot applications are a dime a dozen, and you can do image editing offline, online and even on your phone. So what's a new way that you can make use of image editing... Read More of the software. Resizing and performing other operations on images in bulk is just one more area where IrFanview really excels.

Resizing Images in Bulk

If you use IrFanview, resizing anything from ten to hundreds of images is a breeze.

As an example, I’m going to show you how I recently converted over the images of the Philadelphia City Hall that I took on my trip in May to Philly. I needed these images to be around 450 pixels wide to center on my blog, but straight off my camera they are about 1,200 pixels wide.


bulk resize images

As you can see from the raw list of photos that I downloaded off my camera, this resolution means the file size is pretty large – anything from half a megabyte to one megabyte per image. That just won’t do when you want your website page to have a fast page load speed.

resize images in bulk

To fix this, I needed to convert about 20 photos down to under 100KB each if possible, with a resolution of about 450 pixels wide. IrFanview provides you with a lot of choices to do this without losing much quality when the pictures are viewed online.


Resizing Images In IrFanview In 5 Steps

Performing this task is really easy, and once you get into the habit of using it, you’ll find that the time it takes to resize twenty images one at a time versus the time it takes to do a single five-step bulk-resize is easily cut down by 90%. You will love all of the extra time you have on your hands.

Assuming you have a directory filled with a bunch of huge images that you want to resize, you can get started by opening up the program (download a copy if you don’t have one yet), clicking on the “File” menu, and then selecting “Batch Conversion/Rename” from the list.

resize images in bulk

The page that comes up with appear somewhat complicated, with all sorts of selections, dropdown boxes and choices, but it really isn’t all that bad.


The second step is to tell the conversion tool where your source files are. You do this in the window to the upper right. Just click on the dropdown box where the “Look in” folder is displayed, and change that folder to the one where all of your large images are stored.

Either select the individual images you want to convert, or just click on “Add all” to grab them all. All of the images will show up in the lower text box. Those are the images that are going to be converted.

resize images in bulk

The third step is to tell the converter exactly what output format you want to use. Starting off at the upper left of the window, the first choice you have to cut down on the size of an image is to change the format. You can use the “Output format” dropdown list to do that. If my original is a PNG file, I almost always save it to JPG if I’m going to publish it online.


bulk convert images

The fourth step is to tell the tool how to resize the image. You do this by clicking on the “Advanced” button (right under the “Options” button), and you’ll see a new window pop up with all of your options.

Here, you can set the width to whatever you like in pixels, cm or inches. Beyond resizing in bulk, this impressive tool also lets you change colors and effects, sharpening, changing brightness or cropping the images.

bulk convert images

If you’re resizing, you can also choose to resize in percent rather than use an exact value. In some cases, this can produce better results, especially when you’re dealing with a lot of images in different portrait and landscape formats. It’s also a good idea to make sure “Preserve aspect ratio” is selected so that your images don’t get distorted in the resize process.

Click on OK and you’ll be back to the conversion tool main page again.

The last and final step in the batch conversion process is to set up the output path. Usually, I just create a directory called “small” inside the image directory. You can do this by clicking on the “Use current ‘look in’ directory” button. This saves you the trouble of retyping the entire path of your source images. Then, just type “\small” at the end.

bulk convert images

You can keep the same name for the files by keeping the $N code in the Name Pattern box, or you can append numbers after the images by typing “$N###”, which will append 001, 002 and so on after your output image names.

Click on “Start Batch” and you should see the following conversion progress box pop-up, showing you an “…Ok” status after every image conversion.

How To Convert & Resize Images In Bulk bulkresize8

Once you’re done, you should now see all of your newly resized images with a nice, low manageable file size.

bulk resize images

In just a few clicks and a few seconds, you can convert all of those images in a fraction of the time. As you can imagine, this is one of those secret time-savers that all highly-productive people can make use of. So, give it a try yourself, and join the ranks of extremely productive people all around the world!

Do you bulk-resize? Do you use IrFanview or some other tool? Share your thoughts and insights in the comments section below.

Related topics: Batch Image Editing, Image Converter, Image Editor.

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  1. Adrian Rea
    October 17, 2012 at 11:50 am

    Can I ask/add, you state that you have used set the length of the width to a set number. This is fine if your photos are all the same orientation (portrait or landscape) and no panoramic images. If you are processing a batch with mixed orientation you may get better results setting either the long side or the short side but still keep the aspect ratio. This will give a more uniform quality across the batch.

  2. Andrea Kosteli?
    August 25, 2012 at 6:08 am

    great article... I did use Irfanview when it just started, but lately I use online programs like etc for image editing.
    For resizing images in bulk I use DVD soft collection of programs...

  3. Chris
    August 24, 2012 at 8:09 pm

    This is a great guide/tutorial.

    Can you guys cover this same article but with XnView?

  4. brucej4
    August 24, 2012 at 5:52 pm

    If you love it so much, why do you keep referring to it as IrFanview, when the correct name (as shown in your screen captures) is IrfanView?

    • whs001
      August 27, 2012 at 9:43 pm

      I was going to make the same point myself, although several other readers have also used the correct name IrfanView without explicitly pointing out the error in the article. For more than 16 years, it has been developed and distributed for free by a man named Irfan Skiljan.

  5. Abdallah Hodieb
    August 24, 2012 at 9:31 am

    I use batch resizing in ubuntu . Using package : nautilas-image-manipulator

  6. SRChiP
    August 24, 2012 at 6:52 am

    I just use Light Image Resizer.

  7. zach
    August 24, 2012 at 5:44 am

    Did you tested photo magician? good and blazingly fast especially for one core PCs. I use both programs and i am very happy

  8. Frank D
    August 24, 2012 at 2:00 am

    I've been using this exact same method for batch resizing images for about 3-4 years now. IrfanView is the best image manipulation program available (and free!).

  9. Kaashif Haja
    August 23, 2012 at 11:59 pm

    I'am been using Prish Image Resizer.
    I hope IfranView works better!

  10. nathanurbina
    August 23, 2012 at 8:35 pm

    IrfanView is really good.

    • Shakirah Faleh Lai
      August 23, 2012 at 9:12 pm

      IrfanView did the more than I expected.

  11. GrrGrrr
    August 23, 2012 at 8:03 pm

    It's new to me. Will give it a shot

  12. Gina Shillitani
    August 23, 2012 at 7:57 pm

    I am definitely going to try this. The way I am using now is slow and difficult!

  13. Uncle Vasja
    August 23, 2012 at 7:35 pm

    Great manual. I've long enjoyed IrfanView and got used to it.