GLM 5.2 vs Muse Spark 1.3

Z.ai · China  |  Meta · US · Updated June 2026

Quick verdict

Pick GLM 5.2 for long-horizon agentic coding or project-level software engineering. Pick Muse Spark 1.3 for agentic coding with ~20% fewer tool calls and ~25% fewer tokens than muse spark 1.2 or deepswe v1.1 long-horizon software engineering (75.4). Choose GLM 5.2 if you need self-hosting or data privacy; Muse Spark 1.3 if you want a managed API.

GLM 5.2 (Z.ai, China) and Muse Spark 1.3 (Meta, US) line up two different AI ecosystems against each other — a comparison that is as much about cost philosophy and openness as raw capability. GLM 5.2 is an open-weight reasoning model built for long-horizon coding and multi-step agent workflows — strong and cheap. Muse Spark 1.3 is meta's September 2, 2026 agentic-coding model update, cutting tool calls and token usage versus Muse Spark 1.2 while its highest-reasoning mode remains gated for safety review. They diverge most on price and open vs. closed weights — each quantified below from the models' real specs.

Key differences at a glance

Side-by-side specs

SpecGLM 5.2Muse Spark 1.3
ProviderZ.ai (China) Meta (US)
ReleasedJune 16, 2026 September 2, 2026
Context window1M (~1,500 pages) 1M tokens (~1,500 pages)
Price (in/out)$1.4/$4.4 per 1M tokens $1.25/$4.25 per 1M tokens
Open weight?Yes — self-hostable No — API only
Modalitiestext, code text, image, video
SWE-Bench VerifiedNot published Not published
MRCR v2 @ 1MNot published 98.1%

Who wins what

Long-horizon agentic coding

GLM 5.2

An open-weight reasoning model built for long-horizon coding and multi-step agent workflows — strong and cheap — and its weights are open while Muse Spark 1.3 is API-only.

Project-level software engineering

GLM 5.2

GLM 5.2 lists project-level software engineering among its strengths; Muse Spark 1.3 does not.

Tool use across long-running tasks

GLM 5.2

GLM 5.2 lists tool use across long-running tasks among its strengths; Muse Spark 1.3 does not.

Agentic coding with ~20% fewer tool calls and ~25% fewer tokens than Muse Spark 1.2

Muse Spark 1.3

Meta's September 2, 2026 agentic-coding model update, cutting tool calls and token usage versus Muse Spark 1.2 while its highest-reasoning mode remains gated for safety review — and it runs cheaper at $1.25/$4.25 per 1M tokens.

DeepSWE v1.1 long-horizon software engineering (75.4)

Muse Spark 1.3

Meta's September 2, 2026 agentic-coding model update, cutting tool calls and token usage versus Muse Spark 1.2 while its highest-reasoning mode remains gated for safety review — and it is the newer of the two.

Near-perfect long-context retrieval (MRCR v2 512K-1M: 98.1)

Muse Spark 1.3

Muse Spark 1.3 lists near-perfect long-context retrieval (MRCR v2 512K-1M: 98.1) among its strengths; GLM 5.2 does not.

Lowest cost at scale

Muse Spark 1.3

At $1.25/$4.25 per 1M tokens, it is the cheaper of the two — the gap dominates the bill on high-volume workloads.

Which should you pick?

A cost-sensitive startup shipping high volume

Muse Spark 1.3

At $1.25/$4.25 per 1M tokens it undercuts GLM 5.2, and on millions of tokens that margin decides the monthly bill.

A team with data-privacy or self-hosting needs

GLM 5.2

Open weights let you run it on your own hardware; Muse Spark 1.3 is API-only.

Anyone whose priority is long-horizon agentic coding

GLM 5.2

It is specifically built for that.

Anyone whose priority is agentic coding with ~20% fewer tool calls and ~25% fewer tokens than muse spark 1.2

Muse Spark 1.3

That is its strongest area.

An enterprise with regional data-residency rules

Muse Spark 1.3 or GLM 5.2

Origin (China vs US) affects where data is processed and which compliance regime applies — check the provider's terms for your region.

GLM 5.2: where it fits

An open-weight reasoning model built for long-horizon coding and multi-step agent workflows — strong and cheap. Released June 16, 2026 by Z.ai, it is built for long-horizon agentic coding, project-level software engineering, tool use across long-running tasks, and tops the open-weight intelligence index (SWE-bench Pro 62.1).

Its trade-offs are real: text-only — no native multimodal input, and new release with a limited third-party track record. At $1.4 in / $4.4 out per million tokens, it sits in the mid price band.

Muse Spark 1.3: where it fits

Meta's September 2, 2026 agentic-coding model update, cutting tool calls and token usage versus Muse Spark 1.2 while its highest-reasoning mode remains gated for safety review. Released September 2, 2026 by Meta, it is built for agentic coding with ~20% fewer tool calls and ~25% fewer tokens than Muse Spark 1.2, deepSWE v1.1 long-horizon software engineering (75.4), near-perfect long-context retrieval (MRCR v2 512K-1M: 98.1), and ranks third overall on the Artificial Analysis Intelligence Index (score 61, xhigh variant; the limited-preview max variant scores 62) - behind only Claude Fable 5.1 and Claude Opus 5.

Its trade-offs: strongest 'max' reasoning configuration still gated pending additional safety testing, not yet open-weight, despite Meta roadmapping a future Muse Spark weights release, and no official SWE-bench Verified score published. At $1.25 in / $4.25 out per million tokens, it sits in the mid price band.

The bottom line for this matchup

The defining split here is open vs. closed. GLM 5.2 gives you weights you control — self-host it, fine-tune it, keep data in-house, pay only for hardware. Muse Spark 1.3 gives you a managed, always-updated API with no infrastructure to run. Teams with GPUs, privacy requirements, or huge volume often favour the open model; teams that want zero ops and the latest capabilities favour the closed one. Capability is close enough that this operational question, not the benchmark, usually decides it.

Want both GLM 5.2 and Muse Spark 1.3 without two subscriptions? LumiChats gives you these plus 40+ models under one ₹69/day pass (about $1/day) — draft with one, cross-check with the other.

See pricing

Frequently asked questions

Is GLM 5.2 or Muse Spark 1.3 better for coding?

Public SWE-Bench figures are not available for either model, so the honest test is your own repository — run an identical real bug through both. By design, GLM 5.2 leans toward long-horizon agentic coding while Muse Spark 1.3 leans toward agentic coding with ~20% fewer tool calls and ~25% fewer tokens than muse spark 1.2, and that positioning usually predicts which feels better on your codebase.

Which is cheaper, GLM 5.2 or Muse Spark 1.3?

GLM 5.2 is open-weight, so self-hosting means no per-token fee (you pay for hardware instead), while Muse Spark 1.3 is API-metered at $1.25/$4.25 per 1M tokens. For most teams without GPUs, the API model is cheaper to start; at very high volume, self-hosting can win.

Which has the bigger context window?

Both advertise 1M (~1,500 pages). Remember advertised ≠ usable: recall typically degrades before the ceiling.

Can I use both GLM 5.2 and Muse Spark 1.3 together?

Yes — a multi-model platform like LumiChats gives you GLM 5.2, Muse Spark 1.3 and 40+ others under one ₹69/day pass (about $1/day), so you can draft with one and cross-check with the other instead of buying two subscriptions.

Which is newer, GLM 5.2 or Muse Spark 1.3?

Muse Spark 1.3 — released September 2, 2026, about 3 months after GLM 5.2.

Related comparisons

Specifications and benchmarks reflect publicly reported figures as of June 2026 and may change as providers release updates. Always verify on your own workload.