What Is the GLM Coding Plan?
On March 27, 2026, Z.ai (formerly Zhipu AI) released GLM-5.1 to all Coding Plan subscribers. The GLM Coding Plan is a subscription that gives developers access to Z.ai's language models through tools like Claude Code, Cursor, Cline, and 20+ other AI coding IDEs.
The pitch is simple: get near-Opus-level coding performance for a fraction of the price. But does the reality match?
GLM Coding Plan Pricing
All pricing is verified from z.ai/subscribe as of March 30, 2026:
| Plan | Quarterly Price | Monthly Equivalent | Usage Level |
|---|---|---|---|
| Lite | $30/quarter ($27 from 2nd quarter) | ~$10/month | 3× Claude Pro usage |
| Pro | $90/quarter ($81 from 2nd quarter) | ~$30/month | 5× Lite usage |
| Max | $240/quarter ($216 from 2nd quarter) | ~$80/month | 4× Pro usage |
What's included in all plans: GLM-5.1, GLM-5-Turbo, GLM-4.7, GLM-4.6, and GLM-4.5-Air. Pro and Max users additionally get access to GLM-5. All plans include free MCP tools: Vision Analysis, Web Search, Web Reader, and Zread.
Note: Z.ai removed first-purchase discounts on February 11, 2026. Earlier reports of a "$3/month" plan refer to a promotional price that no longer exists.
The Benchmark: GLM-5.1 vs Claude Opus 4.6
Z.ai tested GLM-5.1 using Claude Code as the evaluation harness across 113 coding tasks. The results, self-reported by Z.ai on March 27, 2026:
| Model | Score (out of 113) | % of Opus |
|---|---|---|
| Claude Opus 4.6 | 47.9 | 100% |
| GLM-5.1 | 45.3 | 94.6% |
| GLM-5 | 35.4 | 73.9% |
GLM-5.1 represents a 28% improvement over GLM-5 — a significant jump for a post-training upgrade released just six weeks after the base model.
Important Caveats
- Self-reported benchmarks: These scores come from Z.ai, not an independent lab. As of March 30, 2026, no third-party evaluation has corroborated the 45.3 score.
- Claude Code as the harness: Using Claude Code as the testing framework may give Claude models a built-in advantage, since Claude Code is optimized for the Claude model family. This makes direct comparison tricky.
- Speed tradeoff: GLM-5.1 delivers 44.3 tokens per second — roughly half the speed of GPT-5.4 and nearly 6× slower than Grok 4.20, according to BridgeBench. For agentic coding workflows where the model works autonomously over long chains, speed matters less. For interactive pair-programming, it's noticeable.
How GLM-5.1 Compares on Independent Benchmarks
While GLM-5.1's self-reported coding score hasn't been independently verified, the base GLM-5 model has been widely benchmarked:
| Model | SWE-bench Verified | License | API Input/Output (per MTok) |
|---|---|---|---|
| Claude Opus 4.6 | ~80.8% | Proprietary | $5.00 / $25.00 |
| Gemini 3.1 Pro | 78.8% | Proprietary | $2.00 / $12.00 |
| GPT-5.4 | 78.2% | Proprietary | $2.50 / $15.00 |
| GLM-5 | 77.8% | MIT (open-weight) | $1.00 / $3.20 |
| Qwen 3.5 (397B) | 76.4% | Apache 2.0 | $0.39 / $2.34 |
| DeepSeek V3.2 | 72–74% | MIT | $0.28 / $0.42 |
GLM-5 at 77.8% on SWE-bench Verified is the highest-scoring open-weight model on this benchmark, and GLM-5.1 should score higher given its post-training improvements — though independent verification is still pending.
The Cost Math: GLM vs Claude
Here's where the GLM Coding Plan gets interesting:
| Plan | Monthly Cost | What You Get |
|---|---|---|
| Claude Pro | $20/month | 5× free usage, all Claude models |
| Claude Max 5× | $100/month | 5× Pro usage, Claude Code included |
| Claude Max 20× | $200/month | 20× Pro usage, Claude Code included |
| GLM Lite | ~$10/month | 3× Claude Pro usage |
| GLM Pro | ~$30/month | 15× Claude Pro usage |
| GLM Max | ~$80/month | 60× Claude Pro usage |
At the Lite tier, you get 3× the usage of Claude Pro for half the price. At Pro, you get 15× Claude Pro usage for $10 more. The value proposition is clear on paper — the question is whether the quality gap justifies the savings.
Where GLM-5.1 Wins
- Long agentic tasks: Z.ai specifically optimized GLM-5.1 for long-horizon coding workflows. If your use case involves multi-step code generation, refactoring, or system architecture tasks, GLM-5.1 shines.
- Cost-sensitive teams: For indie developers, students, or early-stage startups who burn through Claude Pro limits, the GLM Lite plan at $10/month is a compelling alternative.
- Tool compatibility: Works with Claude Code, Cursor, Cline, Kilo Code, OpenClaw, and 20+ other tools — you don't need to change your workflow.
- Open-source trajectory: GLM-5 is MIT licensed on Hugging Face. Z.ai has confirmed GLM-5.1 will also be open-sourced (no date announced), meaning you'll eventually be able to self-host.
Where GLM-5.1 Falls Short
- Speed: At 44.3 tokens/second, GLM-5.1 is the slowest frontier coding model. Claude Opus 4.6 and GPT-5.4 are both significantly faster for interactive coding.
- Unverified benchmarks: The 94.6% claim is self-reported. Until an independent lab confirms it, treat it as Z.ai's marketing number.
- Claude Code advantage: If you're using Claude Code as your primary development tool, Claude's native models will always have a home-field advantage — the tool is literally built around them.
- Ecosystem maturity: Claude and GPT have larger communities, more tutorials, and better-documented edge cases. GLM-5.1's community is growing but still smaller.
The BYOAI Angle
One underappreciated advantage of the GLM Coding Plan is that it works through standard API endpoints. This means you can use it with any platform that supports custom model providers — including BYOAI (Bring Your Own AI) platforms like Serenities AI, where you connect your own model subscription with no AI markup on top.
If you're building apps on a batteries-included platform (with built-in database, auth, storage, and automation), pairing it with GLM-5.1 via BYOAI gives you a full development stack for under $20/month total — compared to $120+ for Claude Max plus separate backend services.
Who Should Subscribe?
| If You... | Choose | Why |
|---|---|---|
| Need the best coding model, period | Claude Max | Opus 4.6 is still #1 on independent benchmarks |
| Want good-enough coding at low cost | GLM Lite ($10/month) | 94.6% of Opus at 50% of Claude Pro's price |
| Burn through rate limits regularly | GLM Pro ($30/month) | 15× Claude Pro usage for $10 more |
| Run heavy agentic workflows | GLM Max ($80/month) | 60× Claude Pro usage, peak-hour performance |
| Want flexibility across models | Both (Claude Pro + GLM Lite) | $30/month total for best of both worlds |
Bottom Line
The GLM Coding Plan at $10/month is the most cost-effective way to access a near-frontier coding model in March 2026. GLM-5.1's self-reported 94.6% of Opus 4.6 performance is impressive if accurate — but it's self-reported, it's slow, and the benchmarks haven't been independently verified.
The smart play for most developers: keep Claude Pro ($20/month) for critical work and add GLM Lite ($10/month) for overflow and agentic tasks. For $30/month total, you get the best of both worlds — Claude's proven quality when you need it, and GLM's deep quota pool when you need volume.