# How strict ist the 30 Mb RAM limit? **URL:** \ **Category:** Developers\ **Tags:** app, homey-pro\ **Created:** [March 16, 2026, 12:45pm UTC](https://community.homey.app/t/how-strict-ist-the-30-mb-ram-limit/152562 "2026-03-16T12:45:30Z")\ **Posts on this page:** 12\ **Page:** 1
**Author:** ![Pascal\_Nohl](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/pascal_nohl/32/164446_2.png) [@Pascal\_Nohl](https://community.homey.app/u/Pascal_Nohl)\ **Post date:** [March 16, 2026, 12:45pm UTC](https://community.homey.app/t/how-strict-ist-the-30-mb-ram-limit/152562/1 "2026-03-16T12:45:30Z")
Hi everyone, In the Developer Tools under **Memory (PSS)**, Homey states: - _A Homey app should not use more than 30 MB of memory._ - _Reduce the number of Node.js modules to use less memory._ How strict is this limit in practice? I have noticed that some apps seem to run well above that threshold. For example, the Shelly app appears to use around **45 MB** , and even **Flow Checker** , which seems to be developed by Athom, uses more than **40 MB**. My own app includes many live devices, polls an inverter frequently, and the next version currently in development will add multiple statistics devices with larger data collections. Because of that, I am finding it difficult to stay below the **30 MB**. So my question is: Is this a hard limit that must always be respected, or more of a guideline as long as the app remains stable and performs well? Best regards, Pascal ---
**Author:** ![robertklep](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/robertklep/32/160628_2.png) [@robertklep](https://community.homey.app/u/robertklep)\ **Post date:** [March 16, 2026, 12:56pm UTC](https://community.homey.app/t/how-strict-ist-the-30-mb-ram-limit/152562/2 "2026-03-16T12:56:07Z")
It’s not strict at all. Apps get “memory warnings” when they use more than 150MB of RAM, and if they do this for more than 50 seconds, they get killed (unless it’s Athom’s own Matter Bridge app, which is allowed to use twice that amount of RAM). If an app uses more than 300MB of RAM, it gets killed immediately. ---
**Author:** ![Peter\_Kawa](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/peter_kawa/32/173848_2.png) [@Peter\_Kawa](https://community.homey.app/u/Peter_Kawa)\ **Post date:** [March 16, 2026, 12:57pm UTC](https://community.homey.app/t/how-strict-ist-the-30-mb-ram-limit/152562/3 "2026-03-16T12:57:46Z")
> [@Pascal\_Nohl](#): > > A Homey app should not use more than 30 MB of memory. AFAIK the mentioned 30 MB limit is a leftover from the (Pro) 2016-2019 models. Some apps use over 40 MB, but that’s exceptional; Those models kill apps using over 80 MB. @ Pro 2023 models and up, some apps use over 125 MB without blinking an eye (‘official’ Matter Bridge app). ---
**Author:** ![Pascal\_Nohl](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/pascal_nohl/32/164446_2.png) [@Pascal\_Nohl](https://community.homey.app/u/Pascal_Nohl)\ **Post date:** [March 16, 2026, 2:35pm UTC](https://community.homey.app/t/how-strict-ist-the-30-mb-ram-limit/152562/4 "2026-03-16T14:35:52Z")
> [@robertklep](#): > > Apps get “memory warnings” when they use more than 150MB of RAM > [@Peter\_Kawa](#): > > Those models kill apps using over 80 MB. Thanks, that clarifies things. I assume you are referring to **RSS** , not **PSS** memory. If so, my app should generally be fine, although on older Homey models I may be getting uncomfortably close to the practical limit. Right now, with **4 regular devices** and **3 statistics devices** created, the app usually stays just below **30 MB PSS** and just below **78 MB RSS**. That said, the PSS does fluctuate from time to time — most often rising to around **31–32 MB** , and in rarer cases up to **39 MB** , before dropping back down again. At this stage, I do not see the typical pattern of a persistent memory leak. My assumption is that these temporary increases are more likely related to Node.js garbage collection behavior, which can be somewhat lazy before reclaiming memory. The main concern for me is therefore not the average memory usage, but the occasional spikes — especially on older Homey models, where an RSS limit around **80 MB** would leave very little headroom. Would that be a fair interpretation? ---
**Author:** ![smarthomesven](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/smarthomesven/32/79712_2.png) [@smarthomesven](https://community.homey.app/u/smarthomesven)\ **Post date:** [March 16, 2026, 8:28pm UTC](https://community.homey.app/t/how-strict-ist-the-30-mb-ram-limit/152562/5 "2026-03-16T20:28:45Z")
> [@Pascal\_Nohl](#): > > For example, the Shelly app appears to use around **45 MB** , and even **Flow Checker** , which seems to be developed by Athom, uses more than **40 MB**. I’ve never seen any app use more than 40MB ![image](https://us1.discourse-cdn.com/flex025/uploads/athom/original/3X/9/4/94ddac3b933c24b4983eec36dbfde7dbfd51e915.png) Also, Flow Checker is developed by a community developer, not by Athom themselves. ---
**Author:** ![Pascal\_Nohl](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/pascal_nohl/32/164446_2.png) [@Pascal\_Nohl](https://community.homey.app/u/Pascal_Nohl)\ **Post date:** [March 16, 2026, 9:40pm UTC](https://community.homey.app/t/how-strict-ist-the-30-mb-ram-limit/152562/6 "2026-03-16T21:40:13Z")
> [@smarthomesven](#): > > I’ve never seen any app use more than 40MB ![image](https://us1.discourse-cdn.com/flex025/uploads/athom/original/3X/e/2/e292751c92455140e366b453d5b9cb87622cd8bf.png) Shelly App. As said, in developer tools app performance PSS 45,2 Mb / RSS 91,3. If you never saw it, here is the evidence. Flow Checker: ![image](https://us1.discourse-cdn.com/flex025/uploads/athom/original/3X/3/2/320732a5fd9fc9ca4b3d1d85438c184946a5bd7b.png) Also 45,6 Mb PSS And, if it is developed by the community, why is it’s dns com.athom ? Strange that Homey accepts such a dns for the community, but apparently it is a community app. ---
**Author:** ![smarthomesven](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/smarthomesven/32/79712_2.png) [@smarthomesven](https://community.homey.app/u/smarthomesven)\ **Post date:** [March 16, 2026, 9:48pm UTC](https://community.homey.app/t/how-strict-ist-the-30-mb-ram-limit/152562/7 "2026-03-16T21:48:20Z")
That’s quite a lot of RAM. I don’t have the “RSS” RAM in my Homey Developer Tools page (only PSS). I’ve never used the Shelly app or the Flowchecker app, but I just checked and the Tuya app uses 31MB of RAM (PSS) which is the highest of all the apps I use (but that can also be because most of my devices are Tuya devices, so it’s busier than the other apps). > [@Pascal\_Nohl](#): > > And, if it is developed by the community, why is it’s dns com.athom ? I don’t know why it shows com.athom, but it’s definitely a community app ![AISelect_20260316_224402_Samsung Internet](https://us1.discourse-cdn.com/flex025/uploads/athom/original/3X/4/5/455ed85542bb4f015739a54d182f30d4378b1af2.jpeg) ---
**Author:** ![Peter\_Kawa](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/peter_kawa/32/173848_2.png) [@Peter\_Kawa](https://community.homey.app/u/Peter_Kawa)\ **Post date:** [March 16, 2026, 10:29pm UTC](https://community.homey.app/t/how-strict-ist-the-30-mb-ram-limit/152562/8 "2026-03-16T22:29:40Z")
It happens, for example MQTT Hub, Home Assistant community, Audit and Homeyscript often use over 40 MB, depending on the number of synced devices, flows and running scripts ![Screenshot_20260316_232418_Homey](https://us1.discourse-cdn.com/flex025/uploads/athom/original/3X/f/4/f4217c5d26ddb5d2f2bc956d97a21abc8e095ac4.jpeg) ---
**Author:** ![Adrian\_Rockall](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/adrian_rockall/32/13209_2.png) [@Adrian\_Rockall](https://community.homey.app/u/Adrian_Rockall)\ **Post date:** [March 17, 2026, 6:45am UTC](https://community.homey.app/t/how-strict-ist-the-30-mb-ram-limit/152562/9 "2026-03-17T06:45:44Z")
Just to add my thoughts, I find that the same app running on a HP2019 will use far less memory than when running on an HP2023 or later. App on my HP2019 ![image](https://us1.discourse-cdn.com/flex025/uploads/athom/original/3X/3/d/3d9febfc5090f9b535c1a414ca0be2fcb0c6c714.png) Same app and same configuration on my HP2026 ![image](https://us1.discourse-cdn.com/flex025/uploads/athom/original/3X/8/4/8480a434a5fc9db9db115459454e462376dd517b.png) ---
**Author:** ![smarthomesven](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/smarthomesven/32/79712_2.png) [@smarthomesven](https://community.homey.app/u/smarthomesven)\ **Post date:** [March 17, 2026, 7:15am UTC](https://community.homey.app/t/how-strict-ist-the-30-mb-ram-limit/152562/10 "2026-03-17T07:15:49Z")
> [@Adrian\_Rockall](#): > > Just to add my thoughts, I find that the same app running on a HP2019 will use far less memory than when running on an HP2023 or later. Then that’s probably the reason why I don’t have any apps that use \>40MB (I use a Pro 2019) ---
**Author:** ![Pascal\_Nohl](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/pascal_nohl/32/164446_2.png) [@Pascal\_Nohl](https://community.homey.app/u/Pascal_Nohl)\ **Post date:** [March 17, 2026, 1:36pm UTC](https://community.homey.app/t/how-strict-ist-the-30-mb-ram-limit/152562/11 "2026-03-17T13:36:55Z")
I’m not completely sure why this happens, but my guess is that it is related to the Node.js garbage collector. For non-developers: when an app frees resources that are no longer needed, that memory is usually not reclaimed immediately. Instead, it is cleaned up later by the garbage collector. Node.js is known for relatively lazy garbage collection, meaning cleanup often happens later rather than sooner. But when available memory becomes more limited, garbage collection can become more aggressive. So on the 2016–2019 Homey models, the system may reclaim memory earlier or more often than on the 2023 model. In my case, the app starts at around 25 MB and then moves up and down, but over several hours it gradually climbs to about 32 MB before suddenly dropping back to around 28 MB, after which the cycle starts again. My assumption is that something in the 25–28 MB range would probably be enough for the app, but since my 2026 Homey has more RAM available, garbage collection may simply be less aggressive. ---
**Author:** ![BasMilius](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/basmilius/32/146560_2.png) [@BasMilius](https://community.homey.app/u/BasMilius)\ **Post date:** [March 17, 2026, 3:35pm UTC](https://community.homey.app/t/how-strict-ist-the-30-mb-ram-limit/152562/12 "2026-03-17T15:35:59Z")
Curious if Python apps have different limits… Otherwise… 🥲 ![image](https://us1.discourse-cdn.com/flex025/uploads/athom/original/3X/5/2/52f52a71b9e204c9b121b2a66bd4494181d8bb5e.png)