Instagram is meant to be a mobile app and, if you can, you should use the Instagram app to upload photos and stories.
If you’re shooting photos with a DSLR or mirrorless camera you know it can be a hassle to get your photos to Instagram. Here is a list of techniques on how to post on Instagram from PC or Mac. This list is up to date with only working apps.
If you don’t have an Instagram account you can sign up on their website.
If you’re having an issue getting photos to your iPhone or Android phone I recommend using Dropbox, AirDroid, or AirDrop to do this task. Every photo I edit in Lightroom is then exported to a Dropbox folder so I can easily post to Instagram with my phone.
There are also apps like Hootsuite and Buffer which will let you write captions beforehand and remind you to post. You can also use the new Instagram draft feature which is built into the Instagram app.
Desktop apps to upload photos to Instagram 
There are a few options to post your photos to instagram from your computer. Here is my list of desktop alternatives to using the app:
Using Instagram’s Mobile Site (Web)
This has to be the quickest and easiest way to use Instagram on any computer. Instagram now offers a mobile version of their site which you can access using by changing your browser’s user agent.
Below is a mini guide on how to change your user-agent in chrome which will allow you to use Instagram’s mobile site.
First open Instagram.com
Then you’ll need to open the developer tools in Chrome which is in the settings bar under More Tools > Developer Tools alternatively you can right click the page and click Inspect as well.
After this is open you can toggle the device toolbar via the Tablet/Mobile button displayed below. This will open the panel to change your user agent.
After this appears you’ll be able to select which device to emulate in chrome. For example sake I chose the iPhone 6 Plus. After doing this you’ll see the Instagram Mobile site which includes a button to upload at the bottom, just like the app.
Note: if it is not working try to refresh the page after changing the user agent.
If you want to use the Instagram mobile site in Safari on mac you can change your user agent using the develop menu. You can do this in the preferences via Safari > Preferences > Advanced where you’ll see the option “Show Develop menu in menu bar“. Once this is enabled you can change your user agent in the develop menu and select iPhone. When you visit Instagram this will bring up the mobile site and allow you to upload.
Using the browser you’ll be able to crop your photo and add a caption but most of the features of the full app are missing.
LR/Instagram Plugin (PC & Mac)
Most photographers edit in Adobe Lightroom on their computer (if you don’t I highly recommend it).
The LR/Instagram plugin allows you to export your photos right from Lightroom to Instagram. This is the perfect solution if your entire workflow is within Lightroom. It does lack a lot of features like tagging users in posts and account switching but if you just want to add your photos to Instagram it’s a great solution.
The plugin allows you to set a caption for your posts via Lightroom’s tags and caption options. Additionally you can upload many photos at the same time.
After editing your photos and adding captions just drag photos you’d like to post to the LR/Instagram gallery. Then, after your posts are ready, just right click “Public Now” and the plugin will upload all of your photos to Instagram.
If you have a Mac Uplet has to be the easiest way to upload photos or video to Instagram.
All you need to do is put in your Instagram username and password; then you can bulk post as many photos as you want. It’s as simple as dragging photos onto the Uplet application.
My favorite option in Uplet has to be the ability to select the ‘crop aspect ratio’ (1.91:1 or 4:5). Basically this lets you upload portrait or landscape photos which was a feature added to Instagram in 2015.
After picking a photo or video all you need to do is add a caption! Sadly two features it’s missing are tagging people within the photo and scheduled posts. It’s still a great way to bulk upload to Instagram or even upload one photo from your Mac.
Gramblr (PC & Mac)
Gramblr is one of the most robust solutions for posting to Instagram from Mac or PC.
Gramblr is a great solution if you have a desktop and want to schedule posts. Your computer must be on (or asleep) when a post is scheduled to work, but that shouldn’t be an issue for desktop users.
Additionally, you can use multiple account within Gramblr, so this is the perfect solution for maintaining and scheduling multiple accounts.
After installing Gramblr it runs locally on your Mac or PC and can be accessed in any web browser.
Gramblr gives you complete control over your posts, including tagging users in pictures. There’s also tools to crop, filter, add text overlays, and frames. Plus basic photo editing options! (But if you’re uploading from a computer I doubt you need them.)
One feature that surprised me was the ability to paste a link from Instagram, Flickr, Youtube, or a slew of other sites to repost on your account. This would be the perfect tool if you run an account that features other people’s photos, but sadly it did not work in my test.
If you’re working with a team of people updating one or multiple accounts Grum.co is a great solution. The only downside is that Grum has a monthly fee and charges to use multiple accounts. It is a simpler solution than other options if you want the ability to schedule posts though.
Grum’s interface allows you to upload photos and videos. After selecting a photo you can crop it and add a caption as you’d expect.
One feature I found useful was the ability to add a first comment. This is great if you like to stuff all of your hashtags in a comment right after posting.
Running Instagram on Desktop (with BlueStacks)
Another option is running the Android Instagram app on your computer. This can be done by running an Android emulator on your Mac or PC with BlueStacks.
It’s the heaviest option since you’ll have to run Android on your computer, so I don’t recommend this option unless you need all of the features.
This is the perfect option if you want a completely native Instagram experience on your computer. Plus you’ll have all of the features of the app including filters, locations, stories, galleries, and account switching.
There are also quite a few other options to post to Instagram from desktop, but above are the best solutions I’ve found.
Again, if you can, I recommend using the Instagram app on your phone. Having access to community features such as commenting and following users is essential to the Instagram experience in my opinion.