Inside GLM-5.5: Zhipu's 1T-Parameter, 1M-Context Open-Weight Contender

GLM-5.5 is an unreleased large language model from Zhipu AI (Z.ai), positioned as the next flagship in the GLM-5 series and targeted for an August 2026 release, according to a JPMorgan research note relayed by Reuters on June 25, 2026. Community leaks between July 14 and July 20, 2026 describe a model with more than one trillion total parameters, a one-million-token context window carried over from GLM-5.2, open weights, and a heavy focus on long-running coding agents. None of these specs are confirmed by Zhipu AI as of this writing — the company's official channels still promote GLM-5.2, and no model card, benchmark, or endpoint for GLM-5.5 has been published.

Key Takeaways

• GLM-5.5 is expected in August 2026 as the successor to GLM-5.2, per a JPMorgan research note echoed by Reuters and CGTN.
• Community leaks put total parameters above 1T, with a 1M-token context window and open weights — all unconfirmed by Zhipu AI.
• Multiple leaks suggest Zhipu may skip GLM-5.3 and GLM-5.4 entirely; version numbering is not final.
• The design focus, per leaks, is long-horizon autonomous coding agents rather than raw chat quality.
• Predecessor GLM-5.2 scored 51 on the Artificial Analysis Intelligence Index and is MIT-licensed open-weight, which sets the baseline expectation for GLM-5.5.
• No official price, model ID, benchmarks, or exact release date have been published as of July 20, 2026.

What Is GLM-5.5?

GLM-5.5 is the next planned entry in Zhipu AI's General Language Model (GLM) series, which the company distributes under its Z.ai product brand. The GLM-5 family began with GLM-5 in February 2026 (a roughly 744B-total, 40B-active mixture-of-experts model), continued with GLM-5.1 in April, and reached GLM-5.2 in mid-June 2026. GLM-5.5 is described in a JPMorgan research note as "the next key milestone in Chinese frontier AI," a phrasing later picked up by Reuters and CGTN.

The model has not been officially announced by Zhipu AI. Everything below the JPMorgan/Reuters "August 2026" line — the parameter count, the context window, the open-weight assumption, the skipped-versions rumor — comes from community reposts and analyst extrapolation. Treat this page as a live reference that will be amended when Zhipu publishes a model card. Readers arriving in search of a spec sheet should note the difference between the two confirmed facts (name and rough timing) and the surrounding cloud of unconfirmed detail.

GLM-5.5 at a Glance

Attribute	Value
Developer	Zhipu AI (Z.ai)
Model family	GLM-5 series
Type	Large language model, likely MoE (unconfirmed)
Modality	Text (multimodal support not yet confirmed)
Total parameters	>1 trillion, rumored (unconfirmed)
Active parameters	Not yet confirmed
Context window	~1M tokens, expected to carry over from GLM-5.2 (unconfirmed)
License	Expected open-weight, likely MIT following GLM-5.2 (unconfirmed)
Release target	August 2026, per JPMorgan/Reuters
Pricing	Not yet confirmed
Availability	Not yet released
Predecessor	GLM-5.2 (June 2026, ~744B total / ~40B active MoE, 1M context)

How GLM-5.5 Works and What Makes It Different

The most substantive technical hint comes from analyst Teortaxes, who wrote that "GLM 5.5 might well be a new and larger pretrain, and one that'll carry them towards Fable/Mythos realm" — his shorthand for the current frontier tier occupied by closed models like Claude Fable 5. He adds a structural observation about the current MoE regime: "pretraining is becoming a rounding error. <100B active MoE just… isn't a big deal." In other words, even a trillion-parameter total model can remain economically trainable and cheap to serve if only a small fraction of experts activate per token, which is the pattern GLM-5.2 established with roughly 40B active parameters.

If the leaked "1T+ total" figure holds, GLM-5.5 would represent a step-change in scale rather than a post-training refresh — closer to the 4→4.5 jump Teortaxes references than the incremental 5→5.1→5.2 cadence. Zhipu's stated design focus, according to community relays of the JPMorgan note, is long-running coding agents: multi-hour autonomous workflows that stress tool use, planning, and context retention rather than single-turn chat. GLM-5.2 already competes near Claude Opus 4.8 on Terminal-Bench and SWE-style tasks at a fraction of the cost, and GLM-5.5 is positioned as the model meant to close the remaining gap.

Three coined anchors are worth tracking as this ships: Mythos-class (the frontier tier Teortaxes says GLM-5.6 or 5.7 may target, per a claim attributed to Zhipu CEO Zhang Peng), Open Fable (community shorthand for an open-weight model matching Anthropic's Fable 5 tier), and IndexShare (the sparse-attention mechanism introduced in GLM-5.2 that GLM-5.5 is expected to inherit or extend).

Source: @teortaxesTex

What You Can Do With GLM-5.5

Based on the design brief that has leaked, GLM-5.5 targets three use categories:

• Long-horizon coding agents. Multi-file refactors, migrations, and repository-scale edits that require the model to keep hundreds of thousands of tokens of code and tool output in view. This is the headline use case in every leak summary.
• Autonomous workflows. Chains of tool calls that run for hours without human intervention — the pattern that GLM-5.2 users have already begun deploying and that GLM-5.5 is meant to make more stable.
• Local and enterprise deployment. If the open-weight assumption holds, GLM-5.5 will be downloadable from Hugging Face like GLM-5.2, which lets teams run it on their own multi-GPU infrastructure instead of paying per-token API fees.

Because nothing is released yet, no third-party benchmarks or production case studies exist for GLM-5.5 itself. The strongest signal is that GLM-5.2 has been adopted for internal routing at Databricks and cited across coding harnesses — a reception that shapes expectations for the successor. Teams that want to prototype similar coding-agent workflows today can start on a comparable open-weight chat model like Kimi K3 and swap in GLM-5.5 when weights land.

How GLM-5.5 Compares

Only rough positional comparisons are possible pre-release. GLM-5.2 is the concrete baseline; the closed-model column is aspirational per community framing.

Model	Params (total / active)	Context	License	Status
GLM-5.5 (rumored)	>1T / not yet confirmed	~1M expected	Expected open-weight	Unreleased, Aug 2026 target
GLM-5.2	~744B / ~40B MoE	1M	MIT open-weight	Released June 2026
Kimi K3	2.5T–2.8T class	1M	Open-weight	Released
Claude Fable 5	Not disclosed	Not disclosed	Closed	Released
Claude Opus 4.8	Not disclosed	Not disclosed	Closed	Released

For a fuller side-by-side on the current generation, see our earlier writeup on GLM-5.3 vs Claude and the deep dive on what Kimi K3 actually ships.

Availability: How to Access GLM-5.5

GLM-5.5 is not yet accessible through any channel. Zhipu AI has not opened a preview, waitlist, or API endpoint, and no model ID string has been published. When the model does ship, the historical pattern for the GLM-5 series is:

• Weights posted to Hugging Face under zai-org/
• A technical blog at z.ai/blog
• API access via docs.z.ai and the Z.ai Coding Plan
• Chat access at chat.z.ai

Users who want an early sense of the family's behavior can use GLM-5.2, which is already available through those same channels. Third-party API resellers are not endorsed here — access should route through Zhipu's official surfaces once the model is public.

What We Don't Know Yet

The list of open questions is longer than the list of confirmed facts:

• Exact release date. "August 2026" is a JPMorgan projection, not a Zhipu commitment.
• Architecture. Whether GLM-5.5 is a scaled-up MoE, a dense model, or something new. Active parameter count is unknown.
• Version numbering. Multiple leaks suggest 5.3 and 5.4 are being skipped, but the final name could still change.
• Multimodal support. GLM-5.2 is text-only; no signal on whether 5.5 adds vision or audio.
• Pricing. No API rate or Coding Plan tier has been announced.
• License. Open-weight is the assumption based on precedent, not a Zhipu statement.
• Benchmarks. No public scores exist on any eval — everything is extrapolated from GLM-5.2's numbers.

Frequently Asked Questions

What is GLM-5.5?

GLM-5.5 is an unreleased large language model from Zhipu AI (Z.ai), targeted for an August 2026 release as the successor to GLM-5.2. Based on a JPMorgan research note relayed by Reuters, it is described as the next milestone in Chinese frontier AI. Rumored specs include more than one trillion total parameters and a one-million-token context window, but no benchmarks or official specs have been published.

When will GLM-5.5 be released?

GLM-5.5 is expected in August 2026 according to a JPMorgan research note cited by Reuters on June 25, 2026, and echoed by CGTN. No exact date has been announced by Zhipu AI, and the company had not officially confirmed the schedule as of late July 2026.

Is GLM-5.5 open source?

GLM-5.5 is widely expected to ship as open-weight, following the MIT-licensed release pattern of GLM-5 and GLM-5.2. This is unconfirmed by Zhipu AI, but every prior model in the GLM-5 series has been open-weight, and community reporting treats it as the default assumption.

How many parameters does GLM-5.5 have?

GLM-5.5 is rumored to exceed one trillion total parameters, up from roughly 744 billion total (about 40 billion active) in the GLM-5.2 MoE. This figure comes from a JPMorgan research note and unofficial community leaks, and Zhipu AI has not confirmed the architecture, active parameter count, or whether it uses a mixture-of-experts design.

What is GLM-5.5's context window?

GLM-5.5 is expected to retain or extend the one-million-token context window that shipped with GLM-5.2. This carry-over is based on community leaks summarizing the JPMorgan note; the final context length has not been confirmed by Zhipu AI.

GLM-5.5 vs Claude Opus 4.8: how do they compare?

GLM-5.5 has not been benchmarked publicly, so any comparison to Claude Opus 4.8 is speculative. Its predecessor GLM-5.2 scored 51 on the Artificial Analysis Intelligence Index and reportedly approaches Opus 4.8 on Terminal-Bench and SWE-style coding tasks at roughly one-sixth the cost, which is why community observers frame GLM-5.5 as a potential open-weight Opus challenger.

Why is Zhipu apparently skipping GLM-5.3 and GLM-5.4?

Community leaks in July 2026 suggested Zhipu AI may jump directly from GLM-5.2 to GLM-5.5, though the reason is unconfirmed. Observers speculate it signals a larger pretraining step rather than an incremental post-training update; Zhipu has not commented, and the version numbering could still change before release.

What to Watch Next

Three signals matter over the next few weeks: an official post on z.ai/blog or a model repo appearing under zai-org/ on Hugging Face; any confirmation of the parameter count and active-expert configuration, which would validate or break the "1T+" leak; and early third-party benchmark runs on Terminal-Bench and SWE-style evals that show whether GLM-5.5 actually closes the gap to Claude Fable 5 and Opus 4.8 on long-horizon coding tasks. This page will be updated as those land.

Building similar long-context coding agents? On kie.ai you can try Kimi K3, Claude Opus 4.8, and GPT-5.6.