Pick Claude Opus 4.8 for agentic coding and multi-file debugging or long autonomous tasks. Pick GLM 5 for agentic planning and long-horizon coding workflows or complex systems design and backend reasoning. Choose GLM 5 if you need self-hosting or data privacy; Claude Opus 4.8 if you want a managed API.
Claude Opus 4.8 (Anthropic, US) and GLM 5 (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. Claude Opus 4.8 is the agentic-coding and judgment leader — highest SWE-Bench Pro score ever recorded at launch. GLM 5 is z.ai's flagship open-weight (MIT) MoE foundation model, engineered for complex systems design and long-horizon agentic coding. They diverge most on price, context window, open vs. closed weights and coding benchmarks — each quantified below from the models' real specs.
Key differences
Price: GLM 5 is about 5× cheaper on input ($1/$3.2 per 1M tokens vs $5/$25 per 1M tokens) — a large enough gap that at scale it can be the single biggest line item in the decision.
Context window: Claude Opus 4.8 holds 5× more — 1M (~1,500 pages) vs 200K (~300 pages). But effective recall usually fades long before the advertised ceiling, so the bigger number only helps if the model reasons over it.
Coding: Claude Opus 4.8 leads SWE-Bench Verified by 10.8 points (88.6% vs 77.8%) — a real edge on hard, real-world software tasks.
Recency: Claude Opus 4.8 is the newer model by about 4 months (released May 28, 2026), usually meaning fresher training data and capabilities.
Ecosystem: this is a US-vs-China matchup — they differ in pricing philosophy, data-residency options, and tooling ecosystems, not only benchmarks.
Specifications
Spec
Claude Opus 4.8
GLM 5
Provider
Anthropic (US)
Z.ai (China)
Released
May 28, 2026
February 11, 2026
Context window
1M (~1,500 pages)
200K (~300 pages)
Price (in/out)
$5/$25 per 1M tokens
$1/$3.2 per 1M tokens
Open weight?
No — API only
Yes — self-hostable
Modalities
text, image, code
text, code
SWE-Bench Verified
88.6%
77.8%
MRCR v2 @ 1M
Not published
Not published
Who wins what
Agentic coding and multi-file debugging: Claude Opus 4.8 — A core design strength of Claude Opus 4.8.
Long autonomous tasks: Claude Opus 4.8 — A core design strength of Claude Opus 4.8.
Honest uncertainty flagging: Claude Opus 4.8 — A core design strength of Claude Opus 4.8.
Agentic planning and long-horizon coding workflows: GLM 5 — A core design strength of GLM 5.
Complex systems design and backend reasoning: GLM 5 — A core design strength of GLM 5.
Iterative self-correction on autonomous tasks: GLM 5 — A core design strength of GLM 5.
Lowest cost at scale: GLM 5 — At $1/$3.2 per 1M tokens, it is the cheaper of the two — the gap dominates the bill on high-volume workloads.
Largest single-prompt input: Claude Opus 4.8 — Its 1M window is about 5× larger, fitting roughly 1,500 pages in one prompt.
Which should you pick?
A cost-sensitive startup shipping high volume: GLM 5 — At $1/$3.2 per 1M tokens it undercuts Claude Opus 4.8, and on millions of tokens that margin decides the monthly bill.
Someone analysing very long documents or codebases: Claude Opus 4.8 — Larger 1M window fits more in one prompt.
A team with data-privacy or self-hosting needs: GLM 5 — Open weights let you run it on your own hardware; Claude Opus 4.8 is API-only.
Anyone whose priority is agentic coding and multi-file debugging: Claude Opus 4.8 — It is specifically built for that.
Anyone whose priority is agentic planning and long-horizon coding workflows: GLM 5 — That is its strongest area.
An enterprise with regional data-residency rules: Claude Opus 4.8 or GLM 5 — Origin (US vs China) affects where data is processed and which compliance regime applies — check the provider's terms for your region.
Claude Opus 4.8: where it fits
The agentic-coding and judgment leader — highest SWE-Bench Pro score ever recorded at launch. Released May 28, 2026 by Anthropic, it is built for agentic coding and multi-file debugging, long autonomous tasks, honest uncertainty flagging, and professional writing and reasoning.
Its trade-offs are real: highest per-token price of the frontier tier, and not the cheapest for high-volume work. At $5 in / $25 out per million tokens, it sits in the premium price band.
GLM 5: where it fits
Z.ai's flagship open-weight (MIT) MoE foundation model, engineered for complex systems design and long-horizon agentic coding. Released February 11, 2026 by Z.ai, it is built for agentic planning and long-horizon coding workflows, complex systems design and backend reasoning, iterative self-correction on autonomous tasks, and open weights under the permissive MIT license.
Its trade-offs: 200K context trails 1M-context rivals, and quickly superseded by GLM-5.1 and GLM-5.2. At $1 in / $3.2 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 gives you weights you control — self-host it, fine-tune it, keep data in-house, pay only for hardware. Claude Opus 4.8 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.
Frequently asked questions
Is Claude Opus 4.8 or GLM 5 better for coding?
On SWE-Bench Verified, Claude Opus 4.8 scores 88.6% and GLM 5 scores 77.8% — Claude Opus 4.8 has the measurable edge.
Which is cheaper, Claude Opus 4.8 or GLM 5?
GLM 5 is open-weight, so self-hosting means no per-token fee (you pay for hardware instead), while Claude Opus 4.8 is API-metered at $5/$25 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?
Claude Opus 4.8 — 1M vs 200K, about 5× larger. Useful only if the model actually reasons over the full window, which not all do.
Can I use both Claude Opus 4.8 and GLM 5 together?
Yes — a multi-model platform like LumiChats gives you Claude Opus 4.8, GLM 5 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, Claude Opus 4.8 or GLM 5?
Claude Opus 4.8 — released May 28, 2026, about 4 months after GLM 5.
Claude Opus 4.8 vs GLM 5
Anthropic · US | Z.ai · China · Updated June 2026
Quick verdict
Pick Claude Opus 4.8 for agentic coding and multi-file debugging or long autonomous tasks. Pick GLM 5 for agentic planning and long-horizon coding workflows or complex systems design and backend reasoning. Choose GLM 5 if you need self-hosting or data privacy; Claude Opus 4.8 if you want a managed API.
Claude Opus 4.8 (Anthropic, US) and GLM 5 (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. Claude Opus 4.8 is the agentic-coding and judgment leader — highest SWE-Bench Pro score ever recorded at launch. GLM 5 is z.ai's flagship open-weight (MIT) MoE foundation model, engineered for complex systems design and long-horizon agentic coding. They diverge most on price, context window, open vs. closed weights and coding benchmarks — each quantified below from the models' real specs.
Key differences at a glance
▸Price: GLM 5 is about 5× cheaper on input ($1/$3.2 per 1M tokens vs $5/$25 per 1M tokens) — a large enough gap that at scale it can be the single biggest line item in the decision.
▸Context window: Claude Opus 4.8 holds 5× more — 1M (~1,500 pages) vs 200K (~300 pages). But effective recall usually fades long before the advertised ceiling, so the bigger number only helps if the model reasons over it.
▸Coding: Claude Opus 4.8 leads SWE-Bench Verified by 10.8 points (88.6% vs 77.8%) — a real edge on hard, real-world software tasks.
▸Recency: Claude Opus 4.8 is the newer model by about 4 months (released May 28, 2026), usually meaning fresher training data and capabilities.
▸Ecosystem: this is a US-vs-China matchup — they differ in pricing philosophy, data-residency options, and tooling ecosystems, not only benchmarks.
Side-by-side specs
Spec
Claude Opus 4.8
GLM 5
Provider
Anthropic (US)
Z.ai (China)
Released
May 28, 2026
February 11, 2026
Context window
1M (~1,500 pages)
200K (~300 pages)
Price (in/out)
$5/$25 per 1M tokens
$1/$3.2 per 1M tokens
Open weight?
No — API only
Yes — self-hostable
Modalities
text, image, code
text, code
SWE-Bench Verified
88.6%
77.8%
MRCR v2 @ 1M
Not published
Not published
Who wins what
Agentic coding and multi-file debugging
Claude Opus 4.8
A core design strength of Claude Opus 4.8.
Long autonomous tasks
Claude Opus 4.8
A core design strength of Claude Opus 4.8.
Honest uncertainty flagging
Claude Opus 4.8
A core design strength of Claude Opus 4.8.
Agentic planning and long-horizon coding workflows
GLM 5
A core design strength of GLM 5.
Complex systems design and backend reasoning
GLM 5
A core design strength of GLM 5.
Iterative self-correction on autonomous tasks
GLM 5
A core design strength of GLM 5.
Lowest cost at scale
GLM 5
At $1/$3.2 per 1M tokens, it is the cheaper of the two — the gap dominates the bill on high-volume workloads.
Largest single-prompt input
Claude Opus 4.8
Its 1M window is about 5× larger, fitting roughly 1,500 pages in one prompt.
Which should you pick?
A cost-sensitive startup shipping high volume
→ GLM 5
At $1/$3.2 per 1M tokens it undercuts Claude Opus 4.8, and on millions of tokens that margin decides the monthly bill.
Someone analysing very long documents or codebases
→ Claude Opus 4.8
Larger 1M window fits more in one prompt.
A team with data-privacy or self-hosting needs
→ GLM 5
Open weights let you run it on your own hardware; Claude Opus 4.8 is API-only.
Anyone whose priority is agentic coding and multi-file debugging
→ Claude Opus 4.8
It is specifically built for that.
Anyone whose priority is agentic planning and long-horizon coding workflows
→ GLM 5
That is its strongest area.
An enterprise with regional data-residency rules
→ Claude Opus 4.8 or GLM 5
Origin (US vs China) affects where data is processed and which compliance regime applies — check the provider's terms for your region.
Claude Opus 4.8: where it fits
The agentic-coding and judgment leader — highest SWE-Bench Pro score ever recorded at launch. Released May 28, 2026 by Anthropic, it is built for agentic coding and multi-file debugging, long autonomous tasks, honest uncertainty flagging, and professional writing and reasoning.
Its trade-offs are real: highest per-token price of the frontier tier, and not the cheapest for high-volume work. At $5 in / $25 out per million tokens, it sits in the premium price band.
GLM 5: where it fits
Z.ai's flagship open-weight (MIT) MoE foundation model, engineered for complex systems design and long-horizon agentic coding. Released February 11, 2026 by Z.ai, it is built for agentic planning and long-horizon coding workflows, complex systems design and backend reasoning, iterative self-correction on autonomous tasks, and open weights under the permissive MIT license.
Its trade-offs: 200K context trails 1M-context rivals, and quickly superseded by GLM-5.1 and GLM-5.2. At $1 in / $3.2 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 gives you weights you control — self-host it, fine-tune it, keep data in-house, pay only for hardware. Claude Opus 4.8 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 Claude Opus 4.8 and GLM 5 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.
On SWE-Bench Verified, Claude Opus 4.8 scores 88.6% and GLM 5 scores 77.8% — Claude Opus 4.8 has the measurable edge.
Which is cheaper, Claude Opus 4.8 or GLM 5?
GLM 5 is open-weight, so self-hosting means no per-token fee (you pay for hardware instead), while Claude Opus 4.8 is API-metered at $5/$25 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?
Claude Opus 4.8 — 1M vs 200K, about 5× larger. Useful only if the model actually reasons over the full window, which not all do.
Can I use both Claude Opus 4.8 and GLM 5 together?
Yes — a multi-model platform like LumiChats gives you Claude Opus 4.8, GLM 5 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, Claude Opus 4.8 or GLM 5?
Claude Opus 4.8 — released May 28, 2026, about 4 months after GLM 5.
Specifications and benchmarks reflect publicly reported figures as of June 2026 and may change as providers release updates. Always verify on your own workload.