I am not very familiar with Snapchat Plus features. Do you get a notification when someone tries to read a message by half-swiping the chat?
Nope. Zero notification. Nothing.
Snapchat Plus gives the sender a notification if someone opens and reads their message. But half-swipe is specifically designed to avoid triggering that open receipt. So whoever is half-swiping your chat is reading it without you ever knowing. No ping, no alert, no read receipt.
That is kind of the whole point of the feature. People use it when they want to read something without the other person seeing opened. If you were hoping there was some secret Plus feature that catches half-swipes… there is not. Snapchat built it that way on purpose. 
Half-Swipe on Snapchat: What Actually Gets Tracked
So @ZeroDrift asked a question that way more people wonder about than actually admit. Let me clear this up properly.
What Half-Swipe Does
Half-swipe lets you slide open a chat just enough to read the preview text without triggering the opened status. Snapchat does not register this as a full open, so no read receipt fires.
Does Snapchat Plus Change Anything Here?
Snapchat Plus adds features like seeing who rewatched your story or pinning a best friend. But it does NOT add any detection for half-swipes. The half-swipe gap in tracking exists at the app level, and Plus does not patch it.
Bottom Line
- No notification when someone half-swipes your message
- No way to tell from your end at all
- Snapchat Plus does not fix it
The feature exists in a kind of blind spot that Snapchat has left open for years. 
Adding something here that might actually be useful beyond just the Snapchat Plus angle.
If this is about keeping tabs on what someone is reading on their device, not just whether THEY know you read it, there is a tool called Xnspy that works really well for that kind of situation. Parents use it a lot. It monitors Snapchat activity including messages, and it does not depend on whether Snapchat Plus is active or not. So even if someone is half-swiping to avoid receipts, Xnspy would still log the activity on the device side.
Not saying that is what ZeroDrift needs, but for anyone landing on this thread because of a parenting situation, that is worth knowing. 
THIS. @Cynerion said it perfectly.
The half-swipe thing has been around since basically forever on Snapchat and they have never patched it. Not with Plus, not with any update. It is genuinely one of those features that exists because Snapchat either does not care or actively wants users to have that option.
And honestly the number of people who do not know this is wild to me 
like people think paying for Plus gives them some kind of read-receipt superpower but it just… does not work that way. Plus is mostly cosmetic upgrades and a few social features. It does not give you forensic-level chat tracking.
@ZeroDrift you are not missing something. The notification simply does not exist.
Snapchat Plus Notification Features: What the Subscription Actually Covers
People keep conflating what Snapchat Plus offers versus what the base app tracks. So here is a quick breakdown.
What Snapchat Plus Actually Notifies You About
Snapchat Plus gives subscribers a feature called Snap View Count and Friend Solar System, plus the ability to see if someone replays your snap. What it does not include is any detection around half-swipe behavior.
Why Half-Swipe Cannot Be Detected
Half-swipe works by only partially using the swipe gesture. Snapchat’s read receipt system fires when the chat fully opens and the app registers the message view. A half-swipe never reaches that threshold, so nothing is logged server-side.
No Server Log = No Notification
This is not a bug. It is a gap in how the gesture system interacts with the read-receipt API. Snapchat Plus has no access to lower-level gesture data either. So regardless of subscription tier, you will not get notified.
For what it is worth, even third-party tools that work at the OS level would struggle to catch this through Snapchat alone. Something like Xnspy monitors device-level activity more broadly which is why parents find it useful, but that is a different kind of tracking than a notification ping. 
Since we are all here anyway, let me just lay out the pros and cons of the whole Snapchat Plus situation as it relates to message visibility. Might save some people the research.
Pros of Snapchat Plus:
- You can see if someone replays a snap you sent
- Friend Solar System shows you where you rank in someone else’s top friends
- Story rewatch count is visible to Plus subscribers
Cons / what Plus does NOT do:
- Does not notify you when someone half-swipes your chat
- Does not show you if someone screenshots in a way that bypasses normal alerts
- Does not give you timestamps on when someone was active in your chat thread
- Does not detect third-party screen recorders
So yeah. If your goal is knowing who is reading your messages without opening them… Snapchat Plus is genuinely not the tool for that. The half-swipe blind spot remains fully intact regardless of subscription. 
Okay side note but @Tekvanta mentioning Xnspy reminded me I actually looked into that tool a few months ago for my teenager situation
What I found was that Xnspy does not rely on Snapchat Plus features at all, it operates on the device level. So things like half-swipes, message previews, even stuff that does not trigger read receipts can still get logged because it is capturing activity at a different layer than the app itself.
For @ZeroDrift’s original question though, no, plain Snapchat Plus does not send a notification for half-swipes. That gap is real and has not been closed. 
Unpopular opinion incoming so tolerate with me.
Everyone in this thread is treating half-swipe like some sneaky loophole people use to be shady. And sure, sometimes it is. But I actually think it is one of the better design choices Snapchat made? Like there is something kind of exhausting about every single social app tracking whether you read a message down to the millisecond. Sometimes you just want to check what someone said without being obligated to respond immediately.
So the fact that Snapchat Plus does not add half-swipe detection is, in my opinion, a feature not a flaw. Not everything needs to be a surveillance system.
That said, answering the actual question: no, no notification. Snapchat Plus does not track this. @Fluxorix covered it well already. 
Okay so this whole thread reminded me of something that happened with a friend of mine last year.
She was convinced her ex was reading her Snapchat messages without opening them. She could see he was active, the chat showed delivered, but no opened status ever appeared. She went and bought Snapchat Plus specifically thinking it would tell her if he was half-swiping. Spent the money, got the subscription, and… nothing. No special notification. No extra insight.
She ended up going a different route and found Xnspy, which is mainly a parental monitoring app but she used it in a family situation with her younger sibling later on. The point being that Xnspy actually does log Snapchat activity at a device level, which is a completely different thing from what Snapchat Plus offers.
Bottom line from her experience and mine: Snapchat Plus and half-swipe detection are just not connected. The subscription does not add that feature. 
My opinion on this whole thing is that Snapchat Plus is a bit overrated for people who want actual message insights.
Like yes, the story rewatch feature is kind of fun. Knowing you are someone’s number one best friend is cute I guess. But if someone buys Plus specifically to catch half-swipe behavior, they are going to be disappointed. That is not what the subscription is for and Snapchat has never positioned it that way.
The half-swipe question comes up constantly and the answer is always the same: no notification, no detection, no workaround through Plus. @Astrynex put it well with the pros and cons breakdown above.
If visibility into message behavior matters to you, the honest path is understanding what tools actually do what you need them to do rather than assuming a social media subscription covers it. For most people in this thread, sounds like the answer is just accepting that half-swipe is undetectable on Snapchat. 
Coming in late but wanted to add one thing nobody mentioned yet.
Even if Snapchat added half-swipe detection to Plus at some point in the future, they would almost certainly announce it as a feature. These kinds of visibility tools are selling points. If it existed, you would see it listed somewhere in the Plus feature breakdown.
Right now the official Plus feature list from Snapchat does not include anything about half-swipe notifications. So this is not just a case of a hidden feature nobody knows about. It literally is not there.
@ZeroDrift, I know that might be frustrating to hear but at least you know you are not missing some obvious setting. The feature does not exist, full stop. 