Gemini 2.5 Pro vs GLM 5.2

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

Quick verdict

Pick Gemini 2.5 Pro for 2m context via api or strong multimodal reasoning. Pick GLM 5.2 for long-horizon agentic coding or project-level software engineering. Choose GLM 5.2 if you need self-hosting or data privacy; Gemini 2.5 Pro if you want a managed API.

Gemini 2.5 Pro (Google, US) and GLM 5.2 (Z.ai, China) line up two different AI ecosystems against each other — a comparison that is as much about cost philosophy and openness as raw capability. Gemini 2.5 Pro is google's previous-gen 2M flagship — still a strong long-context multimodal option. GLM 5.2 is an open-weight reasoning model built for long-horizon coding and multi-step agent workflows — strong and cheap. 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

SpecGemini 2.5 ProGLM 5.2
ProviderGoogle (US) Z.ai (China)
ReleasedJune 2025 June 16, 2026
Context window2M (~3,000 pages) 1M (~1,500 pages)
Price (in/out)$1.25/$10 per 1M tokens $0.98/$3.08 per 1M tokens
Open weight?No — API only Yes — self-hostable
Modalitiestext, image, audio, video, code text, code
SWE-Bench VerifiedNot published Not published
MRCR v2 @ 1MNot published Not published

Who wins what

2M context via API

Gemini 2.5 Pro

A core design strength of Gemini 2.5 Pro.

Strong multimodal reasoning

Gemini 2.5 Pro

A core design strength of Gemini 2.5 Pro.

Science and maths benchmarks

Gemini 2.5 Pro

A core design strength of Gemini 2.5 Pro.

Long-horizon agentic coding

GLM 5.2

A core design strength of GLM 5.2.

Project-level software engineering

GLM 5.2

A core design strength of GLM 5.2.

Tool use across long-running tasks

GLM 5.2

A core design strength of GLM 5.2.

Lowest cost at scale

GLM 5.2

At $0.98/$3.08 per 1M tokens, it is the cheaper of the two — the gap dominates the bill on high-volume workloads.

Largest single-prompt input

Gemini 2.5 Pro

Its 2M window is about 2× larger, fitting roughly 3,000 pages in one prompt.

Which should you pick?

A cost-sensitive startup shipping high volume

GLM 5.2

At $0.98/$3.08 per 1M tokens it undercuts Gemini 2.5 Pro, and on millions of tokens that margin decides the monthly bill.

Someone analysing very long documents or codebases

Gemini 2.5 Pro

Larger 2M 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; Gemini 2.5 Pro is API-only.

Anyone whose priority is 2m context via api

Gemini 2.5 Pro

It is specifically built for that.

Anyone whose priority is long-horizon agentic coding

GLM 5.2

That is its strongest area.

An enterprise with regional data-residency rules

Gemini 2.5 Pro or GLM 5.2

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

Gemini 2.5 Pro: where it fits

Google's previous-gen 2M flagship — still a strong long-context multimodal option. Released June 2025 by Google, it is built for 2M context via API, strong multimodal reasoning, science and maths benchmarks, and whole-book and video analysis.

Its trade-offs are real: superseded by 3.x for newest features, and recall degrades on very long inputs. At $1.25 in / $10 out per million tokens, it sits in the mid price band.

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.

Its trade-offs: text-only — no native multimodal input, and new release with a limited third-party track record. At $0.98 in / $3.08 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. Gemini 2.5 Pro 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 Gemini 2.5 Pro and GLM 5.2 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 Gemini 2.5 Pro or GLM 5.2 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, Gemini 2.5 Pro leans toward 2m context via api while GLM 5.2 leans toward long-horizon agentic coding, and that positioning usually predicts which feels better on your codebase.

Which is cheaper, Gemini 2.5 Pro or GLM 5.2?

GLM 5.2 is open-weight, so self-hosting means no per-token fee (you pay for hardware instead), while Gemini 2.5 Pro is API-metered at $1.25/$10 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?

Gemini 2.5 Pro — 2M vs 1M, about 2× larger. Useful only if the model actually reasons over the full window, which not all do.

Can I use both Gemini 2.5 Pro and GLM 5.2 together?

Yes — a multi-model platform like LumiChats gives you Gemini 2.5 Pro, GLM 5.2 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, Gemini 2.5 Pro or GLM 5.2?

GLM 5.2 — released June 16, 2026, about 13 months after Gemini 2.5 Pro.

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.