Z.ai: GLM 4.5 Air
GLM-4.5-Air is the lightweight variant of our latest flagship model family, also purpose-built for agent-centric applications. Like GLM-4.5, it adopts the Mixture-of-Experts (MoE) architecture but with a more compact parameter...
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Verdict
Best for
- Budget-sensitive long-context tasks
- Chinese-language document analysis
- High-volume text processing pipelines
- Prototyping before scaling to premium models
Strengths
The 128K context window matches GPT-4 Turbo at a fraction of the cost, making it viable for ingesting full codebases or lengthy contracts in a single call. Pricing sits roughly 80% below Anthropic and OpenAI equivalents, which matters for teams running thousands of requests daily. The model originates from Zhipu AI's GLM series, which has shown competitive performance on Chinese-language benchmarks in prior releases, suggesting strength in multilingual scenarios where English-only models stumble.
Trade-offs
Public benchmark coverage is nearly nonexistent, so you're flying blind compared to models with extensive MMLU, HumanEval, and reasoning evals. Early adopters report weaker performance on complex multi-step reasoning and creative writing versus Claude Sonnet or GPT-4o. Output quality can drift on edge-case prompts, and the model lacks the safety tuning depth of Western labs. If your task demands high reliability or passes through compliance review, the lack of transparency becomes a blocking issue.
Specifications
- Provider
- z-ai
- Category
- llm
- Context length
- 131,072 tokens
- Max output
- 98,304 tokens
- Modalities
- text
- License
- proprietary
- Released
- 2025-07-25
Pricing
- Input
- $0.13/Mtok
- Output
- $0.85/Mtok
- Model ID
z-ai/glm-4.5-air
Per-token prices show what the model costs upstream. On Switchy your team draws from one shared org credit pool - one plan, one balance for everyone.
Team cost calculator
5 seats · 80 msgs/day
Switchy meters this against your org's shared credit pool - one plan, one balance for everyone.
Providers
| Provider | Context | Input | Output | P50 latency | Throughput | 30d uptime |
|---|---|---|---|---|---|---|
| z-ai | 131k | $0.13/Mtok | $0.85/Mtok | — | — | — |
Performance
Benchmarks
Works well with
Top MCPs
Compatibility data comes from first-party telemetry; once we have enough co-usage signal, top MCPs for this model will appear here.
How Switchy teams use it
Starter prompts
Bulk Contract Extraction
Extract all payment terms, renewal clauses, and termination conditions from the attached lease. List each with page references and flag any ambiguous language.
Chinese-English Code Comments
Translate all Chinese comments in this Python file to English. Preserve technical terms and keep the tone consistent with existing English comments.
Multi-Document Summarization
Summarize the key findings and methodology from these five papers. Highlight where results conflict and note any shared limitations.
Cost-Optimized Chatbot Backend
You are a support agent for an e-commerce platform. Answer the user's question about order status, refunds, or shipping. Be concise and friendly.
Codebase Context Search
Given this full codebase, explain how the authentication flow works from login to token refresh. Include file names and function calls.
Example outputs
Illustrative - representative of the model's voice and quality, not literal recordings.
Review this Python function for potential bugs and suggest improvements. Focus on edge cases and performance: ```python def merge_sorted_lists(list1, list2): result = [] i = j = 0 while i < len(list1) and j < len(list2): if list1[i] < list2[j]: result.append(list1[i]) i += 1 else: result.append(list2[j]) j += 1 return result ```
The function has a critical bug: it doesn't append remaining elements after one list is exhausted. When the while loop exits, elements from the longer list are lost. Add these lines after the loop: ```python result.extend(list1[i:]) result.extend(list2[j:]) ``` Performance-wise, repeated `len()` calls in the loop condition are inefficient. Cache the lengths beforehand. Also consider that `extend()` is faster than individual `append()` calls for the remaining elements. The function assumes both inputs are already sorted—add a docstring to document this precondition.
This example shows GLM 4.5 Air's ability to identify both correctness issues and performance optimizations in a single pass. The 131K token context window supports reviewing larger codebases, though without public benchmarks we can't verify its accuracy rate against established code-review models like Claude or GPT-4.
Explain the CAP theorem to a junior backend engineer who's choosing between PostgreSQL and Cassandra for a new microservice. Include when each database makes sense.
CAP theorem states distributed systems can guarantee only two of three properties: Consistency (all nodes see the same data), Availability (every request gets a response), and Partition tolerance (system works despite network failures). PostgreSQL prioritizes CP: strong consistency and partition tolerance, but may become unavailable during network splits. Choose it when data correctness is critical—financial transactions, inventory systems, user authentication. Cassandra prioritizes AP: always available and partition-tolerant, but eventual consistency means reads might return stale data briefly. Choose it for high-write workloads where temporary inconsistency is acceptable—activity logs, time-series data, recommendation engines. For your microservice: if you need ACID transactions and immediate consistency, use PostgreSQL. If you need horizontal scaling and can tolerate eventual consistency, use Cassandra.
Demonstrates GLM 4.5 Air's technical explanation capabilities with practical decision-making guidance. The response balances theory with actionable advice appropriate for the stated audience level. At $0.85/Mtok output, this 150-word explanation costs roughly $0.0001—competitive for educational content generation, though the model's teaching accuracy remains unverified without benchmark data.
Draft a professional email declining a vendor proposal. The vendor offered a monitoring solution at $8K/month, but we're already committed to Datadog. Keep it brief and maintain the relationship for future opportunities.
Subject: Re: Monitoring Solution Proposal Hi [Vendor Name], Thank you for the detailed proposal on your monitoring platform. The feature set looks comprehensive, and I appreciate the time your team invested in the demo. After internal review, we've decided to continue with our current Datadog implementation. We've already built significant tooling and runbooks around it, and the switching cost doesn't justify the change at this time. That said, I'm impressed with your alerting capabilities and anomaly detection features. I'd like to stay in touch—our infrastructure needs evolve quickly, and I can see scenarios where your solution might be a better fit down the road. Best regards
Shows GLM 4.5 Air handling business communication with appropriate tone and relationship preservation. The model incorporates the specific context (price point, competitor name, future-proofing language) effectively. However, the 131K context window is overkill for this task—most business emails fit in 4K tokens, so the model's pricing advantage emerges only in long-document workflows like contract analysis or multi-thread email summarization.
Use-case deep-dives
When GLM 4.5 Air makes sense for 500+ daily support tickets
A 12-person SaaS support team routing 600 tickets/day needs fast classification without breaking the budget. GLM 4.5 Air wins here because the $0.13 input price means you can throw full ticket histories (3-4k tokens each) at the model for context without watching costs spiral. The 131k context window handles edge cases where a customer references three prior conversations in one thread. Output is expensive at $0.85/Mtok, but triage responses are short—usually under 100 tokens—so your real cost is input-driven. If your tickets average under 2k tokens or you're generating long summaries (500+ tokens per ticket), switch to a model with cheaper output. For this volume and token profile, GLM 4.5 Air keeps you under $40/day while maintaining full conversation context.
Why GLM 4.5 Air struggles with high-output summarization workloads
A 4-person legal ops team needs to summarize 80 contracts/week into 400-word briefs for stakeholders. GLM 4.5 Air is the wrong call. The $0.85/Mtok output price means each 400-token summary costs $0.34 in output alone—before you factor in the 8-12k token contract input. At 80 contracts/week, you're looking at $110-140/month just in generation costs, and that's assuming single-pass summaries with no revisions. The 131k context window is overkill for standard contracts, and you're paying the output premium for a feature you don't need. Switch to a model with sub-$0.30 output pricing, or if you need the context window for multi-document synthesis, batch your summaries to amortize the cost. GLM 4.5 Air works when input dominates; summarization flips that ratio.
How GLM 4.5 Air handles live 90-minute strategy calls with full context
A 6-person product team runs weekly 90-minute strategy calls and needs real-time action-item extraction without losing thread when someone references a decision from 40 minutes ago. GLM 4.5 Air fits because the 131k context window holds the entire transcript (typically 18-25k tokens for a 90-minute call) plus your extraction prompt. The $0.13 input rate keeps each analysis under $0.05 in input costs, and action items are short outputs (50-80 tokens), so the $0.85 output price stays manageable. You're looking at $0.08-0.12 per meeting for full-context extraction. If your calls run under 45 minutes or you're fine with sliding-window context, cheaper models work. But for long calls where late references matter, GLM 4.5 Air delivers full-meeting context at a price that scales to weekly cadence.
Frequently asked
Is GLM 4.5 Air good for general text tasks?
GLM 4.5 Air handles standard text generation, summarization, and Q&A adequately for most business use cases. With a 131K token context window, it processes long documents without chunking. No public benchmarks exist yet, so performance relative to GPT-4 or Claude remains unverified. Best suited for teams willing to test a newer model at lower cost.
Is GLM 4.5 Air cheaper than GPT-4o or Claude Sonnet?
Yes, significantly. At $0.13 input and $0.85 output per million tokens, GLM 4.5 Air costs roughly 90% less than GPT-4o ($2.50/$10.00) and 95% less than Claude Sonnet 3.5 ($3.00/$15.00). The trade-off is unproven quality — no public benchmarks confirm it matches their reasoning or accuracy. Use it for high-volume, lower-stakes work where cost matters more than top-tier performance.
Can GLM 4.5 Air handle 128K token inputs reliably?
The 131K context window suggests it should, but without published needle-in-haystack or long-context benchmarks, real-world performance is uncertain. Most models degrade in accuracy beyond 64K tokens. Test your specific use case — document analysis, codebase review — before committing to production. If you need proven long-context reliability, Claude 3.5 Sonnet or GPT-4 Turbo are safer bets.
How does GLM 4.5 Air compare to earlier GLM versions?
Z.ai hasn't published comparative benchmarks between GLM 4.5 Air and prior GLM releases, so performance improvements remain undocumented. The "Air" suffix typically signals a lighter, faster variant, implying lower latency or cost versus a standard GLM 4.5. Without data, assume incremental gains rather than a generational leap. Request trial access to compare against your current model directly.
Should I use GLM 4.5 Air for customer-facing chatbots?
Only after thorough testing. The lack of public benchmarks means you can't predict hallucination rates, instruction-following accuracy, or safety guardrails. For customer support where errors damage trust, start with GPT-4o Mini or Claude Haiku — both proven and similarly priced. Use GLM 4.5 Air for internal tools or non-critical automation where you can monitor outputs and iterate quickly.