GLM 5.2 vs Claude 3.5 Sonnet
Zhipu AI's GLM-5.2 — the top open-weight coding model of mid-2026. A ~750B sparse MoE (≈40B active) under an MIT license, with a 1-million-token context window and benchmarks (81.0 Terminal-Bench, 62.1 SWE-Bench Pro) sitting just behind Claude Opus 4.8.
🧠 Expert verdict
Our expert verdict: Claude 3.5 Sonnet is the stronger all-round choice, scoring 4.9/5 versus 4.6/5 for GLM 5.2, and it stands out for "Best writing quality". Choose Claude 3.5 Sonnet if you want the best writing tool overall, especially for long document analysis; pick GLM 5.2 if "Top open-weight coding model (81.0 Terminal-Bench)" matters more for your workflow.
GLM 5.2
Zhipu AI's GLM-5.2 — the top open-weight coding model of mid-2026. A ~750B sparse MoE (≈40B active) under an MIT license, with a 1-million-token context window and benchmarks (81.0 Terminal-Bench, 62.1 SWE-Bench Pro) sitting just behind Claude Opus 4.8.
Claude 3.5 Sonnet
State of the art LLM from Anthropic featuring high code intelligence and brilliant writing.
GLM 5.2
✅ Pros
- +Top open-weight coding model (81.0 Terminal-Bench)
- +Huge 1M-token context window
- +Permissive MIT license for commercial use
- +Beats GPT-5.5 on cost (about 1/6th)
- +Two reasoning modes (High / Max)
❌ Cons
- −~750B params heavy to self-host
- −Less brand recognition outside China
- −Smaller third-party tooling
- −Top mode trades speed for depth
Claude 3.5 Sonnet
✅ Pros
- +Best writing quality
- +Longest context window (200K)
- +Safer & more honest
- +Excellent at coding
- +Less hallucinations
❌ Cons
- −No image generation
- −No voice mode
- −No plugins/extensions
- −Slower than GPT-4
🎯 Best for — GLM 5.2
🎯 Best for — Claude 3.5 Sonnet
🏷️ Tags — GLM 5.2
🏷️ Tags — Claude 3.5 Sonnet
Our Verdict
After comparing ratings, pricing and features, Claude 3.5 Sonnet comes out ahead with a 4.9/5 rating. It is the better choice for most users.
Expert take on each tool
📌 GLM 5.2
GLM-5.2 is the best open-weight model for coding in mid-2026: top open Terminal-Bench score, a 1M-token context window and an MIT license, at roughly a sixth of GPT-5.5's cost. It is the standout choice for teams that want to build on and ship open weights without restrictive licensing.
📌 Claude 3.5 Sonnet
Claude is the best choice for professionals who need high-quality writing, long document analysis and honest, safe AI responses. Superior for coding tasks and research that requires accuracy over speed.
❓ Frequently Asked Questions
Which is better: GLM 5.2 or Claude 3.5 Sonnet?
Claude 3.5 Sonnet has the higher user rating (4.9/5 vs 4.6/5), making it the stronger overall pick. That said, GLM 5.2 can still be the better fit depending on your budget and specific needs — see the full comparison above.
Is GLM 5.2 or Claude 3.5 Sonnet cheaper?
GLM 5.2 (Open weights (MIT) / GLM Coding Plan from $10/mo) and Claude 3.5 Sonnet (Free / $20/mo) sit at a similar price point. The best way to compare actual cost is to check each tool's plans for the specific features and usage limits you need.
Can I switch from GLM 5.2 to Claude 3.5 Sonnet?
Yes — switching between GLM 5.2 and Claude 3.5 Sonnet is usually straightforward since both are writing tools with similar core workflows. Most users can export their data and get started with Claude 3.5 Sonnet within a day; just check Claude 3.5 Sonnet's free plan before committing to a paid tier.