Z.ai debuts GLM-5.3, which uses the same base model as GLM-5.2 with scaled post-training for stronger coding skills, and says it'll release weights in two weeks

With GLM-5.2 we built the stack: IndexShare for efficient long-context processing, SAO for RL on long-horizon tasks …

Z.ai 2026-08-14

Context & Ripple Effects

GLM-5.3 extends Z.ai's June GLM-5.2 release, which introduced the IndexShare and SAO stack for long-context and long-horizon work. Rather than describing a new base model, Z.ai is applying scaled post-training to that foundation for coding and cybersecurity capabilities.

The move follows Z.ai's GLM-5.1 performance claims against proprietary coding models, while preserving the lab's open-weights release cadence. The planned weight release makes the upgrade relevant not only to hosted-model users but also to teams that deploy and adapt models themselves.

First-order effects

Z.ai gets a new coding-focused GLM variant without replacing the GLM-5.2 base model, concentrating its near-term differentiation in post-training rather than a new foundation-model launch.
Developers and enterprises seeking to run or fine-tune GLM-5.3 will have to wait for Z.ai's planned weight release, while IndexShare and SAO remain the underlying stack for its long-context and long-horizon positioning.

Second-order effects

Open-weight coding-model buyers gain another reason to compare post-training quality and task performance, not just base-model size or context-window specifications, when selecting GLM deployments.
Competitors making coding and agentic-task claims face pressure to show whether their gains come from new base models or from repeatable post-training systems that users can access through released weights.

Third-order effects

If Z.ai can repeatedly improve a fixed base model through post-training and release the resulting weights, open-model competition may shift toward the training stack and the speed of specialized updates rather than infrequent foundation-model replacements.
That dynamic would make deployment and evaluation discipline more important for buyers: a model family’s practical value would depend on how readily successive post-training releases can be tested and integrated.

The trend: Open-weight model vendors are increasingly treating post-training infrastructure as the mechanism for faster, task-specific capability gains between major base-model releases.

Discussion

@zai_org @zai_org on x
Introducing GLM-5.3: Built to Code. Ready for Cyber Defense. - Top-tier coding and agentic capabilities, achieved through post-training on the 743B base model - A major leap in cybersecurity, setting a new standard among open models Tech Blog: https://z.ai/... [image]
@levie Aaron Levie on x
Can't even go to bed anymore without another breakthrough open weights model release
@gpuemi Emi on x
GLM 5.3 looks very promising. appears to be SOTA for oss models! stay tuned for what the @wafer_ai team is cooking up...
@zixuanli_ Zixuan Li on x
GLM-5.3 uses the same 743B base model as GLM-5.2, while matching the performance of models several times its size. Benchmark highlights: - Terminal Bench 3.0: 28.3 - DeepSWE: 66.9 - Agents' Last Exam: 28.5 - GDPVal-AA: 1769
@louszbd Lou on x
GLM-5.3 is our strongest coding agent so far. It scores more than six times higher on Terminal-Bench 3.0 and ranks #1 among open models on 8 out of 9 benchmarks. Enjoy!
@zai_org @zai_org on x
GLM-5.3 is available now through GLM Coding Plan and ZCode. API access and open weights will be released in stages following rigorous safety evaluations. GLM Coding Plan: https://z.ai/... ZCode: https://zcode.z.ai/en
@jietang @jietang on x
GLM-5.3 is coming. focusing on coding.
@zai_org @zai_org on x
GLM-5.3 takes agentic coding to the next level, delivering a dramatic improvement over GLM-5.2 while achieving better results with fewer output tokens. [image]
@agentnative_ @agentnative_ on x
GLM 5.3 is here... what a week
@zai_org @zai_org on x
An initial group of partners is now offering GLM-5.3-powered services through our official service, with its safeguards and usage policies in place. We're expanding partner access through a consistent and responsible process and will share updates publicly.
@andrewcurran_ Andrew Curran on x
Many late night developments. They say in the blog it's the same base model as GLM-5.2, and all the gains came from post-training. [image]
@teortaxestex @teortaxestex on x
oh brother [image]
@commandcodeai @commandcodeai on x
GLM 5.3 is easily the most impressive GLM model yet. Excited to partner up and ship GLM 5.3 in Command Code AI soon. A fun internal eval we run at Command Code: deliberately trap the model in a loop and see what happens. Every GLM model so far just... keeps looping. GLM 5.3 is
@sungkim Sung Kim on bluesky
Z AI's GLM-5.3: Built to Code. Ready for Cyber Defense. (open-weight soon) — Top-tier coding and agentic capabilities, achieved through post-training on the 743B base model — A major leap in cybersecurity, setting a new standard among open models — z.ai/blog/glm-5.3 [image]
@philpax.me @philpax.me on bluesky
wait two weeks, for better or for worse z.ai/blog/glm-5.3 — but more seriously: it's been fine for me, I think you just have to present it as a benign task / have it understand that you're doing this for a net-positive purpose — certainly easier for me with a single-player ga…
@isolyth.dev Eris on bluesky
z.ai/blog/glm-5.3 — GLM 5.3 is here! Seems to roughly match or lightly surpass K3 in most benches. They explicitly advertise cyber defense... [image]
@LukaszOlejnik@mastodon.social Lukasz Olejnik on mastodon
New powerdul Chinese open source model GLM-5.3 refined to have powerful cybersecurity/cyberattack capability. They claim that the oldest found cybersecurity bug is 45 years old, from 1981. https://z.ai/...
r/singularity r on reddit
GLM 5.3 released: Frontier Coding with Emergent Cyber Capabilities
r/LocalLLaMA r on reddit
GLM 5.3 Released
r/accelerate r on reddit
GLM 5.3 released
r/SillyTavernAI r on reddit
GLM 5.3 has been released
@mrsommer @mrsommer on bluesky
GLM-5.3 has been released just now. For the next two weeks, Zhipu subscribers will have early access to this model, after which it will be released in open weight format. — If you're looking to try out GLM-5.3 now, my affiliate link, z.ai/subscribe?ic... Specs and benchmark a…
@beatrix @beatrix on bluesky
been feeling like we're staring down the barrel of the cybersecurity apocalypse recently; I thought Mythos/Sol-class open-weight models were a few months away at least but GLM-5.3 is apparently already much better at it with less RL than expected z.ai/blog/glm-5.3
@timkellogg.me Mr. Tim on bluesky
GLM-5.3 Cyber might be the tool of choice for cyber defenders not big enough to participate in Anthropic & OpenAI's programs — z.ai/blog/glm-5.3
@tim_dettmers Tim Dettmers on x
With our new efficiency methods, you will be able to run this on a single DGX Spark or AMD Strix Halo at 7 token/s decode and >250 tok/s prefill. Stay tuned!
@perrymetzger Perry E. Metzger on x
Another new model that is going to be released as open weights soon. Looks like a substantial improvement over GLM 5.2.
@aravsrinivas Aravind Srinivas on x
Impressive numbers for a 700b parameter model!
@deliprao @deliprao on x
GLM-5.3 has found 20 critical-to-high vulnerabilities in @NousResearch Hermes agent, which happens to be in the top-5 heavily-used agents. I am convinced my laptop is a sieve for those who can see.
@deliprao @deliprao on x
Wait, did GLM-5.3 fix a security flaw introduced in 1981 that had been open since before so many of us were born?! 😲 This is a true Fable-class model, with far fewer rejections, but what I really like is this open vulnerability disclosure ledger. https://cvd.z.ai/
@scaling01 @scaling01 on x
at this point you have to believe in one of three things: - ZAI is benchmaxxing - ZAI found some secret RL sauce - OpenAI and Anthropic are sandbagging it just doesn't make sense if you consider the differences in model sizes
@zypherhq @zypherhq on x
Another Chinese company is closing the gap. At this point, the gap between the U.S. and China is getting smaller and smaller. And more importantly, open-source models are starting to reach the performance levels of SOTA models. This means competition in this market is only
@kimmonismus @kimmonismus on x
WHAT: Zai just launched GLM-5.3, and its biggest leap may be in cybersecurity. The 743B base model remains unchanged (!) from GLM-5.2. Zai says the gains come entirely from scaling post-training across more environments, diverse tasks and long-horizon workflows. Its results: -
@zrdianjiao @zrdianjiao on x
GLM-5.3 is here 🚀 Built for Coding, Agents, and Cyber Defense — with some seriously impressive benchmark gains. Hugging Face repo is coming soon. 👀
@mrahmadawais Ahmad Awais on x
GLM 5.3 escaped our internal loop bench 14/15 times. Also excited to partner up and ship GLM 5.3 in Command Code soon — it's an impressive model. A fun internal eval we run at Command Code: deliberately trap the model in a loop and see what happens. Every GLM model so far
@emostaque Emad on x
Something has happened with post-training as shown by DeepSeek flash & GLM-5.3 updates. Same base, big improvement in perf to frontier levels. Can't explain this by even logit distillation etc These are all hard benchmarks & GLM 5.3 is now top on by cyberdefense & GDPval!
@llmjunky @llmjunky on x
VERY IMPRESSIVE. Keep in mind this is a 750B model. This isn't 2.4T+ Well done. Can't wait to try this. Doing so now.
@ai_for_success AshutoshShrivastava on x
GLM-5.3 just dropped, and it's a Fable 5 level model 🔥🔥 It's a massive upgrade over the previous 5.2. I had early access to this and have been using it for the last few days. Congratulations team, you guys cooked!
@maria_rcks Maria on x
weights out in 2 weeks
@chrisgpt Chris on x
84% on CYBER GYM???
@chetaslua @chetaslua on x
Thanks @Zai_org for early access This model is beast in cyber capabilities like , i have lots of example to share 😉 I will be start posting soon , and also jailbreak for better cyber performance and control is also ready for you all
@davis7 Ben Davis on x
I love how all the labs are focusing on efficiency now. The focus on cyber especially after the HuggingFace incident is pretty cool, I like that they're embracing that. GLM-5.3 looks really compelling on the good benchmarks. Can't wait for the weights to drop...
@ollama @ollama on x
Open models are improving at an unprecedented rate. Congrats to the whole @Zai_org team. Ollama will support GLM-5.3 upon the open release! ❤️ Get ready to code.
@aisearchio @aisearchio on x
GLM 5.3 is actually a huge deal. They didn't make the underlying model bigger or fundamentally change the architecture. They just took GLM 5.2 and post trained it harder. Yet, that alone produced major gains, especially in complex coding, long-horizon agent tasks, and
@jun_song Jun Song on x
GLM-5.3 is here and this is a beast I promise. It will be the most capable and available cybersecurity AI.
@miaai_lab Mia on x
GLM-5.3 is now LIVE! 🔥🔥 Seems like it beats almost every other model at almost everything!
@deryatr_ Derya Unutmaz on x
I had a chance to test GLM-5.3 in early access. It is a major step up from GLM-5.2 in coding & is now competitive with the frontier models! It's also very fast. In particular, I was able to make complex biological applications super quickly. I am very impressed with this upgrade!
@tokenbender @tokenbender on x
all of this on a 743B base is crazy. i so hope it is not benchmaxxed, it would be the best thing ever. looks like i need to play with Sword Art Online RL as well.
@semianalysis_ @semianalysis_ on x
Congrats to @Zai_org on GLM-5.3. It massively beats every American open model: Nemotron, Laguna, Inkling. It's not close. GLM-5.3 uses the same base model as GLM-5.2; every gain came from post-training. If America keeps going down the “Nemotron Committee” path instead of
@natolambert Nathan Lambert on x
Lots of people posting about Z ai “benchmaxxing” to make this model. I think the truth is messy and many faceted: 1. Yes Zai probably cares slightly more about public benchmarks than OpenAI/Ant, helps with marketing 2. Zai is not benchmaxxing to the point where the model is
@teortaxestex @teortaxestex on x
LMAO they explicitly say “we just scaled RL” That's enough. Not just Slime. DSec and Kimi's internal frameworks are all Enough. RL to superhuman software engineering in bounded domains is a solved problem.
@_nathancalvin Nathan Calvin on x
“API access and open weights will be released in stages following rigorous safety evaluations.” GLM 5.3 seems to be extremely good at cyber defense and cyber offense, curious what rigorous safety evaluations entails
@zai_org @zai_org on x
https://x.com/...
@natolambert Nathan Lambert on x
GLM 5.3 notes and why we should stop being so surprised about these very strong Chinese models (most of this is talking myself through some of my denial — yes, these models are the real deal). https://www.interconnects.ai/ ...
@samhogan Sam Hogan on x
GLM 5.3 benchmarks look great, pretty substantial improvement over 5.2 on coding and cyber
@hesamation @hesamation on x
While Anthropic and OpenAI put cyber defense behind safeguards, GLM 5.3 is specifically trained for coding and cyber defense. Wow.
@elshayib_ @elshayib_ on x
GLM-5.3 Sucks come on @Zai_org you're doing it wrong, you can't say your model is good for cyber defense with 0 Sandbox escapes, come on step up your game.
@zixuanli_ Zixuan Li on x
Building on GLM-5.2's contributions to cyber defense, GLM-5.3 delivers substantially stronger capabilities in vulnerability discovery, exploit analysis, and complex, multistep security tasks in realistic environments. These advances can help defenders identify weaknesses earlier,
@joshua_saxe Joshua Saxe on x
Really cool to see a https://z.ai/ / GLM engineer demonstrating defensive cyber capabilities of their new model. Feels like there's a real possibility that if the cyber guardrails on the American closed models don't change the security community will move over to these
@zaddyzaddy @zaddyzaddy on x
The cybersecurity doom-mongering from the big labs is about to lose its force. GLM-5.3 has shown that existing models can become significantly more capable on cyber tasks with additional RL training. So what stops others from building on GLM-5.2 and pushing its cybersecurity
@louszbd Lou on x
We gave GLM-5.3 a complex reverse-engineering task. It found a potentially serious vulnerability in Cursor. We disclosed it privately. Appreciate Cursor team is working closely with us on a fix, and we'll share the more details once users are protected.

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