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Image Optimization Tools

9 Best Free Image Optimization Tools for Image Compression

by Jonathan John on Oct 14, 2015

If there’s one way to slow down your site, it’s by uploading all images to your galleries without compressing them.

You see, most gallery images tend to be very sizeable prior to compression. As a result, whenever you insert a gallery into a page, the size of the page will increase significantly, which in turn will cause load times to balloon.

And that is definitely not good. In fact, research shows that for every additional second a website takes to load, the site will see a 7% decrease in conversions. Furthermore, 47% of web users expect a site to load in just two seconds, and 40% won’t wait more than three seconds for a page to load; they’ll just abandon it altogether (Akamai).

So clearly, fast website speeds are crucial to any website. Start increasing your load speed today by using any one of the below 9 tools to optimize your images.

1. Tiny PNG

Tiny PNG is my go-to image optimization tool of choice. Despite the name, Tiny PNG will support compression of both .jpeg and .png image files.

You can bulk upload images with drag and drop (up to 20 at a time, 5 MB max each). Each image can be downloaded straight to your computer or saved to a Dropbox account.

Results: 660 KB to 236 KB (minus 64%)


2. Compressor.io

Compressor.io is another one of my favorite image size optimization tools for one very good reason: it allows you to choose between lossy (picture quality reduction) and lossless (same picture quality) compression. Lossless compression, however, is limited to JPG and PNG images, and the file savings are also typically very small.

Still, the option is available should you want it, and it’s one that none of the other tools offer, save one. So if you often have to use both lossy and lossless compression then Compressor.io is probably the way to go.

It doesn’t allow you to bulk upload images, though, and the single file sizes are limited to 10 MB.

Results (lossy): 660 KB to 370 KB (minus 44%)


Results (lossless): 3.38 MB to 3.35 MB (minus 1%)


3. JPEG Optimizer

JPEG Optimizer does really well at decreasing file size, but unfortunately the compressed image’s quality is noticeably lower than the original’s. Furthermore, the interface only allows you to upload and compress one image at a time, which makes it unfeasible for bulk image compression.

Result: 644 KB to 16.7 KB (minus 97.4%)


4. Optimizilla

Optimizilla is a cool image compression tool that allows you to quickly and easily compress .jpeg and .png image files.

Bulk compression is possible, as you can upload up to 20 images at a time. Furthermore, once the images have been compressed, you can choose to download them either separately, or together in a ZIP archive.

Result: : 644 KB to 424 KB (minus 34%)


One of Optimizilla’s coolest features is its ability to control the quality reduction. You can use a convenient slider to indicate how much you want the quality to be reduced by on a scale of 1-100. The slider will also preview the compressed image for you in real-time so you can judge whether or not it has enough quality.


5. Kraken.io

Kraken is another convenient image optimization tool. It comes with a feature similar to Compressor.io — it allows you to choose between lossy and lossless compression.

You can upload an unlimited number of images, although each image file must be 1 MB or less in size. Kraken also has a pro option for heavy-duty users, which unlocks image resizing, multiple image sources, save to dropbox, and unlimited image file sizes.

Like Optimizilla, you have a bulk upload option and you can also choose to download each compressed image separately or in a ZIP archive.

Result (lossy): 644 KB to 580 KB (minus 10%)
Result (lossless): 644 KB to 647 KB (minus 1%)


6. Ranking Easy Online Image Optimizer

Ranking Easy is a unique image optimizer; even though the interface is a little unpleasant and the site layout doesn’t look very nice, it comes with a unique feature.

You see, as soon as you upload an image, Ranking Easy will compress the image at seven different qualities from a scale of 1-100 (it compresses to 70, 60, 50, 40, 30, 20, and 10).

Thus, for each quality level you can see what the image looks like and what your file size savings are, allowing you to make a better choice for whatever fits your gallery. Unfortunately, the tool also inserts each image directly on the page at whatever its original size may be. So if you have an image that’s wider than your screen, you’ll have to zoom out to get a good idea of the quality.

Result (quality at 70): 644 KB to 300 KB (minus 55%)


7. Resize Photos

Resize Photos is a well-featured image compression tool that allows for some pretty remarkable file size savings.

Before compressing, you can set the width of the optimized image and select the desired quality level from 1-100, in increments of 5.


Result (quality at 70): 644 KB to 54 KB (minus 92%)


8. Compress Photos

Compress Photos is a very simple tool that optimizes your images very well. Although you don’t have any extra features like custom width or quality control, you can bulk upload and compress an unlimited number of .jpeg or .png at once.

Result: 3.2 MB to 330 KB (minus 90%)


9. Convert Image

Convert Image is a highly functional .jpeg compressor with a very simple, step-by-step process. Just upload your image, choose your compression level (anywhere from 1-100 — you can preview a quality level before compressing to it), and download.

You can even convert your JPG image to a BMP, GIF, ICO, PCX, PDF, PNG, PSD, or TIF while you’re at it. My only real complaint is that the UI for this tool looks quite cluttered.

Result: 644 KB to 324 KB (minus 50%)

Convert Image

Over to You

Of the tools mentioned above, my personal favorite is TinyPNG. I love its combination of convenience and sizeable savings. It was the tool I used to compress the file sizes of each of the images in this very post.

However, your needs may be different from mine. Which of these tools do you plan to use to optimize the images in your galleries? Let us know in the comments below!


  1. This is great information. I am a very happy Envira Gallery Pro WordPress user.

    Is there any reason you did not mention some of the many WordPress plug-in options? I use plug-ins tinypng, simple image sizes, and WP Retina 2x, because it makes the workflow effortless. When I upload a photo to my media library it is optimized automatically for all sizes and devices.

    To speed up Envira albums and galleries, I would prefer to see thumbnails loaded in albums and galleries followed by loading the full-size image. It appears full-size images are loaded and resized to thumbnails to avoid another round trip and speed up viewing.

    I’m not a programmer or developer, please let me know if I missing something. My site is DFWCityhomes.

    1. You can choose to have thumbnails loaded by selecting the crop setting in the config, and then you can choose an image size or specify a dimension for cropping.

  2. Hello,
    Thanks for this review.

    I am currently using photoshop’s “save for web” to keep the images below 100kb but the quality is not as good and for the blog I want it to look good, but I also want the page to load so people don’t get annoyed.

    Have you used this feature?

  3. Great list. I’m a big fan of TinyPng, but thought it could be streamlined a bit. Went ahead and took my first pass at a simple Chrome Extension that lets me right-click to optimize and resize in the browser. It’s been a big time-saver for me, so I published it to the Chrome Store for others to try. Take a look and let me know if you have any feedback. It’s pretty basic, but hopefully that’s a good thing! https://tinybeest.com

  4. Hey Jonathan! Thanks for sharing this information – appreciate the effort you put in !
    You really rocked it, i was searching for best image compression tools online then I found your pretty awesome blog which cleared my each and every doubts.
    I favorite image compression tool is ‘compressor.io’ , it’s really very easy to use in one step. You should check it out once…
    Thank you have a great day

  5. Really it’s a great share. yet I didn’t use this tools- Kraken and Optimizilla. here have found lots tricks and few another tutorials impressed me on both tutorials. Also have enough interest on WebP tools but that can’t see it here. This tools activities are available here http://managemytraffic.com/blog/7-ways-to-image-web-optimization/
    Dear Admin, can you please share about WebP tools because I wanted to know more details about it.

  6. Very nice list! Another tool like these is Tonomatograph.com. They have free and cool flyers, A3 posters, A4 presentations and other templates.

  7. Having recently moved from the Mac to Windows I was looking for something to compress my iPhone photo collection (nearly 200,000 photos). I tried a few of the apps mentioned here and quickly had to rule out the online versions (too many files to upload) and found that the download ones either couldn’t handle the numbers (failed or required too much manual work) or (and this is personal choice) were just too, well, ugly (I’m from the Mac world, I expect pretty). As I’d just bought a new Windows 10 PC, and being used to an App Store, I found a few there but a lot of crap compared to th Apple Store. It was fruitful though and I found one that met all my needs so I thought I’d share it as it’s not on this list. “Batch Image Compressor”
    I hope that helps anyone moving from Mac or just looking for decent photo compressor. Maybe add it to the list?

  8. Hi guys, we are moving over to WordPress from a HTML site we are in the building desiging stage we are wedding photographers wwww.geelongweddingphotographer.com.au and edit in Lightroom and Photoshop however over the years found we need more compression with no or little than no decrease in quality so have been looking for programs that plug into lightroom have been looking at Jpegmini just need advice if this is the best? and are the plugins in WP excellent in their compression. to increase speed of loading and keeping quality ? any one have advice

  9. Thank you for the great plugin list. I was searching best image optimization plugin for my site. Finally i found it and usingWP Smush. It works well as i expected.

  10. Xnview or Xnview MP have image options for different images, jpeg quality, png compression levels, also image bit depths. For example, half-tone images typically allow lower bit depths which can reduce image file size by nearly 50% without losing much quality. Use it’s viewer to test the final quality first, write down the settings and set them in it’s xbs scripts for batch processing in the future.

  11. For me what works best on mac is a combination of Jpegmini and optimimage.
    I usually do it 2-3 times each for the same photo until I get what I want.

  12. I am just learning the basics of on-site SEO, I was surprised by how
    it was so in-depth-luckily I had a few useful blogs though
    Bookmarked your blog, I have to keep up to date with your posts

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