New Reddit immediately results in memory usage spiking to 2 GB

Post by **jobbautista9** » 2025-11-17, 12:01

Operating system: Windows 11 x64
Browser version: 33.9.1
32-bit or 64-bit browser?: 64-bit
Problem URL: https://www.reddit.com/r/touhou (example subreddit which immediately shows the problem, you can get it in the homepage too but it takes a while)
Browser theme (if not default): Default
Installed add-ons: None (fresh profile)
Installed plugins: (about:plugins): Flash, Silverlight, VLC

If possible, please include the output of help->troubleshooting information (as text):

I've been trying to avoid the redesign (i.e. new.reddit.com or www.reddit.com if you haven't opted-out of the redesign from settings) like the plague but there are times I accidentally stumble into it, and looks like this time I've found a pretty nasty bug in the way it makes the browser allocate memory. I've tested a fresh profile to be sure it's not my add-ons interacting badly, and yep unfortunately it looks like whatever Reddit is doing is causing the browser to use so much RAM immediately.

I've attached measurements from about:memory.

Toolkit Error Console:

Code: Select all

Timestamp: 11/17/2025 19:48:36
Error: ReferenceError: PerformanceObserver is not defined
Source File: https://www.reddit.com/r/touhou/
Line: 75

Timestamp: 11/17/2025 19:48:37
Error: ReferenceError: PerformanceObserver is not defined
Source File: https://www.redditstatic.com/shreddit/en-US/aSeIBui8.js
Line: 5

Timestamp: 11/17/2025 19:48:38
Error: The resource from “https://www.reddit.com/r/touhou/apply-polyfill-qHX7md7_.js/” was blocked due to MIME type mismatch (X-Content-Type-Options: nosniff).
Source File: https://www.reddit.com/r/touhou/
Line: 0

These TypeErrors repeat plenty of times:

Code: Select all

Timestamp: 11/17/2025 19:48:48
Error: TypeError: Argument 1 of Document.elementFromPoint is not a finite floating-point value.
Source File: https://www.redditstatic.com/js/concat?prefix=en-US/&chunks=--hrZ0ic,-P8IiWEQ,17GJFXY4,3zL-_W4r,518GFOUw,6m81Q1LD,6vNfluW-,76sLs0ev,7OzNMfw9,7aRFkCvx,7arRBFBv,8NkhRDwv,9SPCVmFT,Ayk5LJnN,B1ifKIur,B4GaGWj0,B4mjqXko,B50STit_,B64cDNdA,B9isht7e,BBCIxAti,BBCIxAti,BC-FMRqo,BCrC5zbt,BDq_P-MU,BFNHFqr9,BFdjgDi5,BG4JboXM,BGLu35XP,BGZyUlE2,BH9WNVBX,BKFENmMx,BKTgmJwY,BL_vDcn7,BLa5KHrZ,BNdapgtU,BOisb71b,BPlEA6nm,BPuUhP4r,BQrtBViG,BRAMSYxM,BT33S23s,BTzv_xNS,BUlIifCf,BVBCL1S4,BXaZrsX4,BXtsnCck,BXyT2i7-,BYxMwh4A,BbxehI_n,Bd7dUC32,BddQy8wl,BewC0M4T,Bf3YOQgE,BfQA7hJT,Bfh3jKDu,BfjqYn9_,Bfpqh88x,Bg14R7bz,BhgD8oza,BhkCph_r,BivcB6Ab,BjyocMfh,BkG1ljOc,BkbeeMYM,BliFE6uV,Blr1Fo8Q,Bm-b8UXY,Bn2roha-,BnK7dos2,BnxUq3UN,Bp_t0gOJ,BqHQzxrA,Brs9gcHl,BsWu10Y5,BvG8Ax3t,BvU94QU8,BwmVBZAv,BwphOMAJ,BxJ5Yasj,BxSm4vbU,Bz4ESs9U,BzKCCU4d,C-7w6AaO,C-HBeSeX,C-VW8RbH,C1CQmo4t,C1bKFnM6,C1wvl9HE,C2IJB4Eq,C3VpiTOj,C4OEPpSZ,C6-Gb8r1,C8nYflDL,C95CGnxf,C9Q6GEhs,C9Q844nI,C9W_Orry,CAlZDII5,CCTxkbfR,CCy9Lsb6,CD7uvS8v,CDFlkf3V,CELZ73D8,CERYkG4Y,CGFonuKN,CGzEIBwW,CHj-JKKJ,CHpxTlYC,CI3kycBc,CI4_9r3K,CIvI-utt,CJ9C1hYz,CKWT3zw7,CLfSv5qs,CMBCvpIz,CMLuHsaL,CNS-XAe7,CPJV3Pk1,CQi0q7k0,CR4qMhM_,CSF10cB6,CS_WZRNv,CTXazJ80,CU4mObWU,CVqqTxtO,CWHTDI7A,CWIlZ9Le,CWMjmnHX,CYGXQzhV,CYrjqNPV,C_J6ajke,C_NdT1sT,Ca6XYVan,CarWZwd2,Cb3Q_3ag,CbQkrdAt,Cd62CP4b,CdOV20Pz,CevBUN0s,ChCuEhnj,CiVT0Pyn,CjRRBDxc,CjaoUJsj,Ckff_xuS,ClxvXASM,CmBIwOJX,Cn_yOP0m,CoALe2X6,CoszrkzZ,Cp5qRibs,Cpivznnw,Cqe4yIps,CsHg7tz4,Csfdzp9J,CspOH70Q,CtlFgudy,CuqB3Ftn,Cx-tw_7M,Cx_iLm3G,CyJv5f1M,Cz6JQ4cO,D0PYrhg6,D106vqnB,D1O5OXF3,D1l4BIvy,D3jVP6ku,D48f7tUA,D73xn7Mp,D7ozApcg,D8IQQavh,D8sD_VVN,DB89F4tZ,DBJU6pZy,DBYWJo6_,DDWPzyy8,DEV65NhQ,DEwARFGt,DFXlXdX-,DFnNeEpQ,DGc9D6Wx,DGc9D6Wx,DGgTs3-c,DGypJcY0,DHfDkeWr,DJ1TcRrK,DLXjMlis,DM4ZQYXh,DMg8FyH5,DNSZj9yg,DNX34Irm,DOenb5TR,DOq240xh,DQZr2BY2,DQqHiNjG,DTUUCfKM,DUYl1yB_,DVLF2Lhk,DWMgcX4H,DWNEEYDX,DWhIli2T,DYjWLIy-,D_2L5Nma,Dd8RZ1JX,DdIwQUSk,DfS-JezI,DjmuZHh5,Dl_W82VP,DmOPAZgO,DmSo1NC-,DmWmSOQU,Do0cZI4s,DrO0CeZY,Dra0mfBF,DreNfxuu,DsedqGI6,Dt3nC6IX,Dv14MvZ0,DxW5Ecyv,Dxq2r908,Dy-D5adS,ED2SYGwe,EhnnnI8b,FV1HSdSR,GpYiY0h7,HV3rrrdt,I8f4071u,IJt-dmHl,JQPvo_K3,JkZ1iw9Z,K7gkL9Oc,LuKxxYUj,LuKxxYUj,Np13HxgU,P1RoeXxU,PAtjyudI,PS39bFnC,Papdg-Gs,QCFSFLcS,QqSXuQxy,SRFOI44i,T60nE6yH,TC9gnkab,THx_Fx-c,Tn7_ihkC,W7CF65Zc,Wkd5pPnN,Z7IFH-FM,ZhWSWTFP,ZvSXbCJW,ZvSXbCJW,b_JBazkt,cn9NqREE,d_Por94l,fLMwo-Ml,fMgUVwG8,gBZyzTaM,gYO545FN,hC4ZCbqO,hJwHftQ8,hkDf4wrv,iYAazVKT,iwfexbr6,jKR4eax7,p029eHMt,pNN2iDbS,pps2QdrH,pqCIHno0,rPGPQWBN,sQhIZia-,shA5tH7L,tkKn_bHw,tqAt4ywN,vZsR0ce6,wtgAGEEx,xaKtIAYM,z4zlAcOS
Line: 461

Timestamp: 11/17/2025 19:48:49
Error: TypeError: (intermediate value).carouselSlot.getAnimations is not a function
Source File: https://www.redditstatic.com/js/concat?prefix=en-US/&chunks=--hrZ0ic,-P8IiWEQ,17GJFXY4,3zL-_W4r,518GFOUw,6m81Q1LD,6vNfluW-,76sLs0ev,7OzNMfw9,7aRFkCvx,7arRBFBv,8NkhRDwv,9SPCVmFT,Ayk5LJnN,B1ifKIur,B4GaGWj0,B4mjqXko,B50STit_,B64cDNdA,B9isht7e,BBCIxAti,BBCIxAti,BC-FMRqo,BCrC5zbt,BDq_P-MU,BFNHFqr9,BFdjgDi5,BG4JboXM,BGLu35XP,BGZyUlE2,BH9WNVBX,BKFENmMx,BKTgmJwY,BL_vDcn7,BLa5KHrZ,BNdapgtU,BOisb71b,BPlEA6nm,BPuUhP4r,BQrtBViG,BRAMSYxM,BT33S23s,BTzv_xNS,BUlIifCf,BVBCL1S4,BXaZrsX4,BXtsnCck,BXyT2i7-,BYxMwh4A,BbxehI_n,Bd7dUC32,BddQy8wl,BewC0M4T,Bf3YOQgE,BfQA7hJT,Bfh3jKDu,BfjqYn9_,Bfpqh88x,Bg14R7bz,BhgD8oza,BhkCph_r,BivcB6Ab,BjyocMfh,BkG1ljOc,BkbeeMYM,BliFE6uV,Blr1Fo8Q,Bm-b8UXY,Bn2roha-,BnK7dos2,BnxUq3UN,Bp_t0gOJ,BqHQzxrA,Brs9gcHl,BsWu10Y5,BvG8Ax3t,BvU94QU8,BwmVBZAv,BwphOMAJ,BxJ5Yasj,BxSm4vbU,Bz4ESs9U,BzKCCU4d,C-7w6AaO,C-HBeSeX,C-VW8RbH,C1CQmo4t,C1bKFnM6,C1wvl9HE,C2IJB4Eq,C3VpiTOj,C4OEPpSZ,C6-Gb8r1,C8nYflDL,C95CGnxf,C9Q6GEhs,C9Q844nI,C9W_Orry,CAlZDII5,CCTxkbfR,CCy9Lsb6,CD7uvS8v,CDFlkf3V,CELZ73D8,CERYkG4Y,CGFonuKN,CGzEIBwW,CHj-JKKJ,CHpxTlYC,CI3kycBc,CI4_9r3K,CIvI-utt,CJ9C1hYz,CKWT3zw7,CLfSv5qs,CMBCvpIz,CMLuHsaL,CNS-XAe7,CPJV3Pk1,CQi0q7k0,CR4qMhM_,CSF10cB6,CS_WZRNv,CTXazJ80,CU4mObWU,CVqqTxtO,CWHTDI7A,CWIlZ9Le,CWMjmnHX,CYGXQzhV,CYrjqNPV,C_J6ajke,C_NdT1sT,Ca6XYVan,CarWZwd2,Cb3Q_3ag,CbQkrdAt,Cd62CP4b,CdOV20Pz,CevBUN0s,ChCuEhnj,CiVT0Pyn,CjRRBDxc,CjaoUJsj,Ckff_xuS,ClxvXASM,CmBIwOJX,Cn_yOP0m,CoALe2X6,CoszrkzZ,Cp5qRibs,Cpivznnw,Cqe4yIps,CsHg7tz4,Csfdzp9J,CspOH70Q,CtlFgudy,CuqB3Ftn,Cx-tw_7M,Cx_iLm3G,CyJv5f1M,Cz6JQ4cO,D0PYrhg6,D106vqnB,D1O5OXF3,D1l4BIvy,D3jVP6ku,D48f7tUA,D73xn7Mp,D7ozApcg,D8IQQavh,D8sD_VVN,DB89F4tZ,DBJU6pZy,DBYWJo6_,DDWPzyy8,DEV65NhQ,DEwARFGt,DFXlXdX-,DFnNeEpQ,DGc9D6Wx,DGc9D6Wx,DGgTs3-c,DGypJcY0,DHfDkeWr,DJ1TcRrK,DLXjMlis,DM4ZQYXh,DMg8FyH5,DNSZj9yg,DNX34Irm,DOenb5TR,DOq240xh,DQZr2BY2,DQqHiNjG,DTUUCfKM,DUYl1yB_,DVLF2Lhk,DWMgcX4H,DWNEEYDX,DWhIli2T,DYjWLIy-,D_2L5Nma,Dd8RZ1JX,DdIwQUSk,DfS-JezI,DjmuZHh5,Dl_W82VP,DmOPAZgO,DmSo1NC-,DmWmSOQU,Do0cZI4s,DrO0CeZY,Dra0mfBF,DreNfxuu,DsedqGI6,Dt3nC6IX,Dv14MvZ0,DxW5Ecyv,Dxq2r908,Dy-D5adS,ED2SYGwe,EhnnnI8b,FV1HSdSR,GpYiY0h7,HV3rrrdt,I8f4071u,IJt-dmHl,JQPvo_K3,JkZ1iw9Z,K7gkL9Oc,LuKxxYUj,LuKxxYUj,Np13HxgU,P1RoeXxU,PAtjyudI,PS39bFnC,Papdg-Gs,QCFSFLcS,QqSXuQxy,SRFOI44i,T60nE6yH,TC9gnkab,THx_Fx-c,Tn7_ihkC,W7CF65Zc,Wkd5pPnN,Z7IFH-FM,ZhWSWTFP,ZvSXbCJW,ZvSXbCJW,b_JBazkt,cn9NqREE,d_Por94l,fLMwo-Ml,fMgUVwG8,gBZyzTaM,gYO545FN,hC4ZCbqO,hJwHftQ8,hkDf4wrv,iYAazVKT,iwfexbr6,jKR4eax7,p029eHMt,pNN2iDbS,pps2QdrH,pqCIHno0,rPGPQWBN,sQhIZia-,shA5tH7L,tkKn_bHw,tqAt4ywN,vZsR0ce6,wtgAGEEx,xaKtIAYM,z4zlAcOS
Line: 371

The PerformanceObserver error and TypeErrors also appear in the devtools web console. These informational messages that only appear in the devtools also seem interesting:

Code: Select all

Navigation API not supported, loading polyfill  
https://www.redditstatic.com/shreddit/en-US/aSeIBui8.js:2:156001

Navigation listeners online  
https://www.redditstatic.com/shreddit/en-US/aSeIBui8.js:2:156293

Mæstro · Post by **Mæstro** » 2025-11-17, 14:57

Off-topic:
Did somebody say… ‘Touhou’?

therube · Post by **therube** » 2025-11-17, 18:36

(I'll just note...

CPU usage subsides at some point
Memory usage does not. For me, it was ~3.8 GB RAM.
And that said, one is likely to be hit again on opening a different link.

FF shows way more content, including ads, then PM, & the "page" acts like an "endless" page - keep on scrolling down, & more shows up.
SeaMonkey shows far less content then PM, but does not run into CPU/RAM issues.)

Post by **moonbat** » 2025-11-18, 02:30

jobbautista9 wrote: ↑
2025-11-17, 12:01
there are times I accidentally stumble into it

Use URL Rewriter configured like so and you'll never run into it.

Screenshot_20251118_132803.png

Gemmaugr · Post by **Gemmaugr** » 2025-11-18, 11:06

Or this GreaseMonkey script:

Code: Select all

// ==UserScript==
// @name        Good old Reddit
// @description	Good old Reddit.
// @version		1.0
// @match       *://www.reddit.com/*
// @exclude      https://*.reddit.com/poll/*
// @exclude      https://*.reddit.com/gallery/*
// @exclude      https://*.reddit.com/media*
// @exclude      https://*.reddit.com/notifications
// @exclude      https://chat.reddit.com/*
// @run-at      document-start
// @grant       none
// ==/UserScript==

if ( window.location.host != "old.reddit.com" ) {
    var oldReddit  = window.location.protocol + "//" + "old.reddit.com" + window.location.pathname + window.location.search + window.location.hash;
    window.location.replace (oldReddit);
}

When voting or viewing polls, I just change old.reddit to sh.reddit

Post by **Moonchild** » 2025-11-22, 16:58

I've done some research and the new Reddit interface has 2 interconnected user-facing problems: potential CTD (crash to desktop) and memory inflation.

As far as I can tell the crash is a consequence of the memory inflation bug which seems to be a javascript race condition in the site's scripting (not something we can fix, this is script-dependent and likely only avoided by mainstream browsers because they process the relevant code slower/more asynchronous). The result is that DOM nodes get added and removed in rapid succession, creating an issue where our garbage collector gets either confused or gets fed not-fully-initialized objects, causing the crashes.

I patched the crashes (Issue #2869 (UXP)) but the memory inflation can't be helped on our end. I concluded it was a race condition because if the browser's JS processing is deliberately slowed down (e.g. by switching to a different tab which throttles timers in the reddit tab), the inflation immediately stops and does not return.
When all reddit tabs are closed (which leaves behind a detached window that will become a ghost window) and ghostbuster kicks in, which can take a few minutes or can be manually triggered (e.g. by forcing a cycle collection in about:memory or simply opening and closing a new tab), memory use in the browser should return to normal.

Post by **jobbautista9** » 2025-11-23, 06:15

Ah, I didn't even know it could get that bad; crashing to desktop that is lol. Thanks for looking into this!

Post by **Moonchild** » 2025-11-23, 11:14

jobbautista9 wrote: ↑
2025-11-23, 06:15
Ah, I didn't even know it could get that bad; crashing to desktop that is lol. Thanks for looking into this!

Yeah it did. I guess my setup is fast enough to really push it into that danger zone (nothing extraordinary though: AMD 5700X, low latency DDR4, on a relatively clean OS) and it was easily reproducible on a fresh build (which tends to fly just after compilation, probably most filesystem stuff still cached in ram on a pristine profile).

Pale Moon forum

New Reddit immediately results in memory usage spiking to 2 GB Topic is solved

New Reddit immediately results in memory usage spiking to 2 GB

Re: New Reddit immediately results in memory usage spiking to 2 GB

Re: New Reddit immediately results in memory usage spiking to 2 GB

Re: New Reddit immediately results in memory usage spiking to 2 GB

Re: New Reddit immediately results in memory usage spiking to 2 GB

Re: New Reddit immediately results in memory usage spiking to 2 GB

Re: New Reddit immediately results in memory usage spiking to 2 GB

Re: New Reddit immediately results in memory usage spiking to 2 GB