GLM-5.3
Released Aug 14, 2026 · knowledge cutoff unpublished
- Status
- Unknown
- Location
- China
- Modality
- Text
- Context window
- 1M
- Max output
- 128K
- Speed
- —
- Price ($/MTok in / out)
- — / —
- Cost per task
- —
- Open weights
- No
Benchmarks1 of 8 reported
Terminal-Bench 2.1
MMLU-Pro
GPQA Diamond
SWE-bench Verified
AIME (latest)
Humanity's Last Exam
LMArena Elo
ARC-AGI-2
Strengths & weaknesses
Strengths
- Independently drives front-end builds, bug fixes and refactors through repeated self-verification to a deliverable state with little hand-holding
- Finds and triages real vulnerabilities at scale — Z.ai's own evaluation run surfaced thousands of flaws across public repositories
- Reaches a meaningfully higher agentic ceiling than 5.2 without a larger base model — the entire gain came from more post-training, not more parameters
Weaknesses
- Still a step behind the closed frontier on the single hardest coding problems, even as it closes most of the gap on everyday agent work
- Good at finding exploitable bugs but weaker at writing the exploits itself — defensive security strength doesn't carry over to offensive tasks
- Weights are held back behind a safety review at launch, so self-hosting and local fine-tuning aren't possible yet
Same ~744B-parameter (~40B active) MoE base as GLM-5.2 — Z.ai's own framing is 'scaling post-training is all we did for GLM-5.3' — so predecessorId is left null per this site's rule against lineage/build-upon language as replacement evidence, even though several outlets call GLM-5.2 its 'predecessor.' Z.ai's launch benchmark table is entirely agentic/coding/cyber (Terminal-Bench 2.1 88.2%, Terminal-Bench 3.0 4.6%→28.3%, DeepSWE v1.1 46.2%→66.9%, SWE-Marathon v1.1 19.4%→42.5%, AutomationBench 26.2%→48.2%, Agents' Last Exam 23.8%→28.5%, CyberGym 84.5% — ahead of Claude Mythos 5's 83.8% and GPT-5.6 Sol's 83.6% by Z.ai's account) and doesn't touch the site's tracked knowledge/reasoning keys, consistent with the unchanged-base-model claim. Context window and max output are carried over unchanged from GLM-5.2 (1M / 128K) pending a dedicated 5.3 model card. No public per-token API pricing yet — available today only via the GLM Coding Plan subscription (Lite/Pro/Max monthly plans) and a staged API rollout; Z.ai says open weights follow in roughly two weeks after safety hardening, at which point openWeights/license/pricing should be revisited.
For developers
API model strings
Not researched
Licence
Proprietary — weights not released
Retirement
No retirement announced
Lineage
No recorded predecessor