When comparing WeChat vs Skype, the Slant community recommends Skype for most people. In the question“What are the best messaging apps for Android?” Skype is ranked 33rd while WeChat is ranked 44th. The most important reason people chose Skype is:
There's a good chance that whoever you're trying to reach has Skype already set up and familiar with it, avoiding the hassle of installing and getting to know new software.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Friends can be added by scanning a QR code
WeChat generates a QR code for each user that other can be scanned to add them as a friend.
Pro Can be used as a Walkie Talkie
WeChat has push-to-talk functionality that can be used both one-on-one and in groups.
Pro Large collection of animated stickers
Pro Easy to send voice messages
Users can record a voice message from within the app to then send it to a recipient, who can then play the message from within the app. It is all self contained.
Pro Enables meeting new people
WeChat has a feature that pairs random people for a conversation. It is activated by shaking the phone (requires location sharing to be enabled) and will present a list of people who are doing the same and how far away from you they are.
Another feature for meeting new people is the Friend Radar that will display people in your vicinity that can then be added to your contacts list.
Finally, there is the People Nearby feature which allows you to send and receive greetings from people in your vicinity.
Pro Moments social network is seamlessly incorporated
Pro Flexible creation of chat groups
You can create chat groups for up to 500 people.
Pro Filters for photos
WeChat includes a collections of filters that can be applied to photos to change how they look.
Pro Easily connect with others due to how popular the service is
There's a good chance that whoever you're trying to reach has Skype already set up and familiar with it, avoiding the hassle of installing and getting to know new software.
Pro Screen sharing
You can show your whole desktop, a select part of the screen or a specific window over Skype.
Pro Cross-platform
There's software for Windows, Mac & Linux and apps are available on iPhone, Android, and Windows Phone.
Pro Group video for free
You can hold video calls with up to 10 people.
Pro Available on Linux
A stripped down, minimalist version of Skype is available for Linux.
Pro File sharing
Skype allows you to send any files (MP3s, images, text, etc.) by simply dragging and dropping then in the chat window making it simple to share things with colleagues.
Pro Cheap fixed phone number
Starting at $5/mo you can get a Skype number.
Pro Send SMS and make regular calls
With Skype Credit bought or a subscription, you can send SMS and make direct calls.
Pro Group chat with archive / records
Pro Powerful 1:1 chat and also group chat
Cons
Con Notifications get muted after inactivity
New message notifications stop getting pushed if the application isn't opened for some extended period of time (seems to be around a week or so)
Con WeChat complies with China's requirements to hand over data
Con Conversations and chat groups aren't ported to new devices
Messages are stored on each device, so shifting to a new device means losing all the previous conversations, as well as an inability to post in previous chat groups until someone else posts there and you're alerted of a new message.
Con User base outside of China is comparatively small
While WeChat has over 400 million users the majority of them are in China. Adoption in other markets has been slow.
Con Plagued by bugs on all platforms
Crashes and other bugs are prevalent on Android, Windows and other platforms.
Con Subpar video quality with more than 5 users
Skype has significant problems with multiple users and video quality. Skype recommends that a max of 5 users group chat as video quality is severely affected. Even webcams tested with other chat services showed lower quality when used with Skype.
Con Not a feasible alternative as a professional team chat
Missing key feature such as centralized mgmt, centralized billing, data retention policies, ...
Con Poor quality when screensharing
It is not possible to manually set resolution or bitrate, and Skype often defaults to a resolution so low that text is unreadable. It is also not possible to transfer control over mouse and keyboard.
Con Slow filesharing speed

Con Owned by Microsoft
Con Obnoxiously large ads
Ads take up over 25% of the usable space.
Con Poor Linux support
The version available for linux users is quite outdated, and does not support some of the newer functionality, such as the free group video calling and screen sharing.
Con Requires both ends to be online (if neither end is using a cloud-enabled device)
Messages are sent and received only when both ends are online, if neither end is using a cloud-enabled device. In this case, if you are online 9-17 and your recipient is online 18-3, messages will never be delivered.
Con MIcrosoft (Skype's owner) actively assists eavesdroppers
On the other hand, if you lose your copy of one of your conversations, you may be able to get a copy of it from your government with a little bit of luck and a public records request.
