While there is simply no comparing robust photo editors like Photoshop or Gimp to online alternatives, sometimes a simple online tool is all you need to get the job done. Whether it's content aware cropping and filling, applying filters and textures, or even doing a little bit more Photoshop-like tasks like using a cloning stamp, there's a wide array of online tools that will get the job done, and for free.

We've put together a list of four online tools that should be in the arsenal of any photographer, designer, or blogger, making it easy to get basic photo editing tasks done on the fly, and in some cases, even on your mobile phone. In no particular order, here they are.

Content Aware Cropping with Croppola

If you're looking for the perfect way to crop your photos online, look no further than Croppola.

The free online service goes beyond giving users a way to simply crop images. Croppola provides users with content aware cropping, meaning that it will suggest, based on your image, how it should be cropped.

Upload your image to Croppola, and choose the dimensions of your new cropped image - the options include maintaining the image's aspect ratio, square, 4:3, 3:2, 16:9 and more. It even has a setting to crop an image to the Facebook timeline's cover photo.

After choosing the crop, you can download the cropped image to your computer.

With Croppola, you can crop multiple images on the website, and download them all as a zipped file. Find out more about Croppola here.

Content Aware Filling with WebInPaint

While Photoshop offers users a great content-aware filling feature, not everyone can afford Photoshop. If you want to use the feature online, give WebInPaint a try. The free service allows users to upload images to the website. Simple swipe over the parts of the picture that you want removed, and WebInPaint will do the rest.

For a free, online service, WebInPaint works surprisingly well. We tested the service with busy photos filled with distractions that we wanted removed, we tried it with simple images, removing just one element, we tried it with black and white photos and color, and in all situations, it was able to successfully remove the parts of the image we didn't want. An example can be seen below. Before putting the image in WebInPaint it looked like this:

And after removing one element from the photo, this is what it looked like:

Robust Photoshop Features with Pixlr

If you're looking for an all-in-one online photo editor, Pixlr is one of the most robust options out there. We're also big fans of the fact that it looks and feels a lot like Photoshop, making it pretty easy to use. You can upload images directly to the site, or even just import an online image using the direct link to the JPEG. Another great feature that Pixlr offers users is the ability to create new images with transparent backgrounds, so you can create PNG logos without having to worry about having access to Photoshop.

Pixlr is packed with basic and advanced editing features - from cropping and resizing to a clone stamp, magic wand, layer,s and much more. Pixlr is also available as a mobile app.

Apply Filters with PicMonkey

With an Instagram-led obsession with filters, no online photo editors list would be complete without at least one option which gives users access to lovely vintage filters. PicMonkey definitely fits the bill with a ton of filters to choose from. Not all of them are available for free however, with some features limited to paying members. A membership will set you back $4.99 a month.

Other than adding filters, PicMonkey also provides users with basic photo editing features, retouching, adding text, frames and textures to images, and more. Find out more about PicMonkey in our in-depth review here.

What are your must-have online photo editors? Let us know in the comments.