GLM 5.2 vs Grok Code Fast 1

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

Quick verdict

Pick GLM 5.2 for long-horizon agentic coding or project-level software engineering. Pick Grok Code Fast 1 for fast, cheap agentic coding at $0.20/$1.50 or low-latency code generation and terminal tasks. Choose GLM 5.2 if you need self-hosting or data privacy; Grok Code Fast 1 if you want a managed API.

GLM 5.2 (Z.ai, China) and Grok Code Fast 1 (xAI, 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. Grok Code Fast 1 is xAI's speed-tier coding model at $0.20/$1.50 with a 256K window — cheap, fast agentic code over frontier quality. They diverge most on price, context window and open vs. closed weights — each quantified below from the models' real specs.

Key differences at a glance

Side-by-side specs

SpecGLM 5.2Grok Code Fast 1
ProviderZ.ai (China) xAI (US)
ReleasedJune 13, 2026 August 28, 2025
Context window1M (~1,500 pages) 256K (~384 pages)
Price (in/out)$1.4/$4.4 per 1M tokens $0.2/$1.5 per 1M tokens
Open weight?Yes — self-hostable No — API only
Modalitiestext, code text, code
SWE-Bench VerifiedNot published Not published
MRCR v2 @ 1MNot published Not published

Who wins what

Long-horizon agentic coding

GLM 5.2

Its 1M window holds about 3.9× more than Grok Code Fast 1's 256K in a single prompt.

Project-level software engineering

GLM 5.2

An open-weight reasoning model built for long-horizon coding and multi-step agent workflows — strong and cheap — and it carries the larger 1M context.

Tool use across long-running tasks

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 Grok Code Fast 1 is API-only.

Fast, cheap agentic coding at $0.20/$1.50

Grok Code Fast 1

At $0.2/$1.5 per 1M tokens it undercuts GLM 5.2 ($1.4/$4.4 per 1M tokens), and that gap compounds at volume.

Low-latency code generation and terminal tasks

Grok Code Fast 1

XAI's speed-tier coding model at $0.20/$1.50 with a 256K window — cheap, fast agentic code over frontier quality — and it runs cheaper at $0.2/$1.5 per 1M tokens.

High-volume coding pipelines where speed beats peak quality

Grok Code Fast 1

Grok Code Fast 1 lists high-volume coding pipelines where speed beats peak quality among its strengths; GLM 5.2 does not.

Lowest cost at scale

Grok Code Fast 1

At $0.2/$1.5 per 1M tokens, it is the cheaper of the two — the gap dominates the bill on high-volume workloads.

Largest single-prompt input

GLM 5.2

Its 1M window is about 3.9× larger than Grok Code Fast 1's 256K, fitting roughly 1,500 pages in one prompt.

Which should you pick?

A cost-sensitive startup shipping high volume

Grok Code Fast 1

At $0.2/$1.5 per 1M tokens it undercuts GLM 5.2, and on millions of tokens that margin decides the monthly bill.

Someone analysing very long documents or codebases

GLM 5.2

Larger 1M window fits more in one prompt.

A team with data-privacy or self-hosting needs

GLM 5.2

Open weights let you run it on your own hardware; Grok Code Fast 1 is API-only.

Anyone whose priority is long-horizon agentic coding

GLM 5.2

It is specifically built for that.

Anyone whose priority is fast, cheap agentic coding at $0.20/$1.50

Grok Code Fast 1

That is its strongest area.

An enterprise with regional data-residency rules

Grok Code Fast 1 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 13, 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.

Grok Code Fast 1: where it fits

XAI's speed-tier coding model at $0.20/$1.50 with a 256K window — cheap, fast agentic code over frontier quality. Released August 28, 2025 by xAI, it is built for fast, cheap agentic coding at $0.20/$1.50, low-latency code generation and terminal tasks, high-volume coding pipelines where speed beats peak quality, and a 256K window sized for real codebases.

Its trade-offs: text and code only — no image, audio or video input, xAI did not publish a SWE-Bench Verified score, a speed-tier coding model, not a frontier reasoner, and narrow focus — built for code, not general knowledge work. At $0.2 in / $1.5 out per million tokens, it sits in the budget 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. Grok Code Fast 1 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 Grok Code Fast 1 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 Grok Code Fast 1 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 Grok Code Fast 1 leans toward fast, cheap agentic coding at $0.20/$1.50, and that positioning usually predicts which feels better on your codebase.

Which is cheaper, GLM 5.2 or Grok Code Fast 1?

GLM 5.2 is open-weight, so self-hosting means no per-token fee (you pay for hardware instead), while Grok Code Fast 1 is API-metered at $0.2/$1.5 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?

GLM 5.2 — 1M vs 256K, about 3.9× larger. Useful only if the model actually reasons over the full window, which not all do.

Can I use both GLM 5.2 and Grok Code Fast 1 together?

Yes — a multi-model platform like LumiChats gives you GLM 5.2, Grok Code Fast 1 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 Grok Code Fast 1?

GLM 5.2 — released June 13, 2026, about 10 months after Grok Code Fast 1.

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.