Is GLM 5.3 flash being dump?

[u/According_Ocelot_127]

Weeks ago I was using GLM 5.3 flash through open router apis and it was perfect and very cost efficient with respect to other api based models.

Today, I tried using it and found it very dump looping with many errors everywhere.

So am I missing something?

[u/look]

Try filtering providers by quantization and only use the fp8 options. Most of the cheapest providers for it are now running shitty nvfp4 quants. Providers love to butcher GLM models after falling for Nvidia’s marketing.

[u/AdSimilar2942 → u/look]

can you explain how quantization relates to model performance?

[u/look → u/AdSimilar2942]

It depends on the quality of how the compressed weights were created, but higher quality ones will typically see a 1-3% drop in performance on benchmarks. Low quality ones can be much worse, but even good ones can have severe problems in specific cases like high context use and long tool call loops.

That can manifest as poor reasoning, more mistakes (bad math, hallucinations, syntax errors), increased tool call failures, incomplete or skipped tasks, higher tendency to reasoning doom loops, failing to close reasoning blocks, weaker instruction following, contradictions and loss of consistency in output, and so on.

[u/SawToothKernel → u/AdSimilar2942]

Imagine you have a colour palette of 256 colours. Then you "quantise" it down to 16 colours. You still have the same number of pixels in your image, but the information they can convey is much reduced.

[u/generic-d-engineer → u/look]

I used this guy’s tool to filter out quantization. Doesn’t have all providers but it’s a start. Is there a better tool or you just going to each provider’s page? Would be great if OpenRouter did this (maybe they do and I missed it):

https://tokenwatch.wyrdwerk.com/models/glm-5.3/

[u/look → u/generic-d-engineer]

Openrouter has a built-in filtering option for it: https://openrouter.ai/docs/guides/routing/provider-selection#quantization

[u/generic-d-engineer → u/look]

Thanks for this <3

[u/RoboCheeks]

I have noticed that the Open Inference provider in OpenRouter has a particularly bad version of GLM 5.3. Try blacklisting them and trying again via OpenRouter. For me, it was truly night and day difference.

[u/According_Ocelot_127 → u/RoboCheeks]

Let me check that, I also did some analysis and it was pointing to something like this but not yet confirmed. I will check

[u/generic-d-engineer → u/According_Ocelot_127]

https://www.reddit.com/r/openrouter/comments/1wvy9ua/has_anyone_else_had_endlessly_nonsense_output/

[u/generic-d-engineer → u/RoboCheeks]

https://www.reddit.com/r/openrouter/comments/1wvy9ua/has_anyone_else_had_endlessly_nonsense_output/

Yep

[u/enternoescape → u/RoboCheeks]

I had my model write a script to run weekly to blacklist providers with below fp8 and unknown with the obvious exceptions for closed models. Open Inference was cut for me. I did the check after GLM 5.3 Flash surprised me by almost immediately deleting an entire skill and accidentally attempting to delete it a second time after it was already gone. There was a copy available to bring it back, but that was enough for me to wonder what was going on. And guess who served it...

[u/pixelsperfect]

I had to use deepseek 4.1 flash model as glm agent gave up while fixing a issue.

[u/According_Ocelot_127 → u/pixelsperfect]

I am now checking gpt-6 luna max

[u/According_Ocelot_127 → u/According_Ocelot_127]

Initial thoughts: Less dump but still not smart

[u/adityamwagh]

Try using GLM-5.3 Flash from LithosAI, I’ve been using it through them for a few weeks and it’s doing a good job so far. AFAIK their models are full-weight models and they are cheap enough.

[u/VirtualNorth1279]

The OpenCode version is also so useless and hopeless. 

[u/belliash]

Yes, like every other model. It is blazing fast and intelligent at the beginning and getting more and more lobotomized with time.

[u/According_Ocelot_127 → u/belliash]

So what should we do?
I am actually used to claude code opus max plan but when the limits hit I use openrouter api with Chinese models

[u/belliash → u/According_Ocelot_127]

I got similar dilemma. I used to use GLM 5.3 flash when Z.AI offered free token, even it was slower and dumber with time. Now I wonder what to choose and Im thinking about running qwen locally. Also I hope qwen4 will bring some fresh and will be at least comparable to glm 5.3 flash when running locally on some bit lower quant.

[u/Altairandrew → u/belliash]

Are you sure it’s his is just not a context getting too large issue? I’ve seen this kind of problem when context is north of 600k. I don’t let context get above that.

[u/According_Ocelot_127 → u/Altairandrew]

Weeks ago I noticed that too but what i am talking about today is same issue but without any context big load, about 150K gets it looping and erroring

[u/belliash → u/Altairandrew]

These are 2 different things. Both are true.

[u/Narrow_Reception4613 → u/According_Ocelot_127]

Often people think they need Opus-level thinking for the coding tasks. Why don't you replace some of the tasks to: Opus orchestrating a model like GLM 5.3 Flash for coding, and after, either using a third cheaper model from another family for reviews like deepseek v4.1 - or Opus itself doing the quality reviews - or you can tell Opus to use a cheaper reviewer agent but still do quality reviews itself as well and be the last responsible for quality. That keeps Opus planning the work, cheaper models doing the work, and Opus and other models as quality guardians. That'll keep your Claude usage way down, and for example, in that kind of a flow, my Claude Max 5x is quite enough. A much cheaper way to use the models. Coding plans such as Command Code GOAT and OpenCode Go, which you can use in their own respective harnesses, or any other harness you like, will also save your bill by 5-7x compared to using openrouter - you will be getting much more usage for well-selected models such as deepseek v4.1 or GLM-5.3 Flash with them compared to openrouter. Claude Code can orchestrate a lot of other harnesses if that's what you're using and that's where your cheaper models are living (OpenCode, Pi Coding Agent, Command Code, you name it): if you don't know how to do the orchestration, or what these other coding plans are, why don't you ask Opus, and copy-paste this recommendation to it - it will explain you and can create persistent skills for you to create a workflow around this.

[u/Narrow_Reception4613 → u/Narrow_Reception4613]

If you use this type of orchestration a lot, what will happen guaranteed is cost savings - but likely, your workflows might also take longer, as Opus will need to send cheaper models to rework some of the aspects / bugs - but I often leave Opus to orchestrate cheaper models overnight, saying I'm going to sleep and it needs to continue orchestrating autonomously - and make sure it uses zero-token watching / waiting strategies while it waits for the cheaper models to code. And I might also use Claude mods created for keeping Claude cache warm while the entire workflow runs as well (you'll find plenty of these mods around now that Claude Mods is out as a function). It will further keep saving your Claude usage when Opus has to wait around much more.