Claude Haiku 4.5 vs GLM 5.1

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

Quick verdict

Pick Claude Haiku 4.5 for fastest claude model or low-latency, high-volume api calls. Pick GLM 5.1 for long-horizon autonomous agentic engineering (up to 8-hour runs) or state-of-the-art open-weight coding (topped swe-bench pro at launch). Choose GLM 5.1 if you need self-hosting or data privacy; Claude Haiku 4.5 if you want a managed API.

Claude Haiku 4.5 (Anthropic, US) and GLM 5.1 (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 Haiku 4.5 is anthropic's fastest, most compact model — built for speed and volume. GLM 5.1 is an open-weight (MIT) Chinese coding model built for long-horizon agentic engineering, topping SWE-Bench Pro at launch while running autonomously for up to 8 hours. They diverge most on price and open vs. closed weights — each quantified below from the models' real specs.

Key differences at a glance

Side-by-side specs

SpecClaude Haiku 4.5GLM 5.1
ProviderAnthropic (US) Z.ai (China)
ReleasedOctober 15, 2025 April 7, 2026
Context window200K (~300 pages) 200K (~300 pages)
Price (in/out)$1/$5 per 1M tokens $1.4/$4.4 per 1M tokens
Open weight?No — API only Yes — self-hostable
Modalitiestext, image, code text, code
SWE-Bench VerifiedNot published Not published
MRCR v2 @ 1MNot published Not published

Who wins what

Fastest Claude model

Claude Haiku 4.5

A core design strength of Claude Haiku 4.5.

Low-latency, high-volume API calls

Claude Haiku 4.5

A core design strength of Claude Haiku 4.5.

Real-time interactions

Claude Haiku 4.5

A core design strength of Claude Haiku 4.5.

Long-horizon autonomous agentic engineering (up to 8-hour runs)

GLM 5.1

A core design strength of GLM 5.1.

State-of-the-art open-weight coding (topped SWE-Bench Pro at launch)

GLM 5.1

A core design strength of GLM 5.1.

Sustained tool use across thousands of calls

GLM 5.1

A core design strength of GLM 5.1.

Lowest cost at scale

Claude Haiku 4.5

At $1/$5 per 1M tokens, it is the cheaper of the two — the gap dominates the bill on high-volume workloads.

Which should you pick?

A cost-sensitive startup shipping high volume

Claude Haiku 4.5

At $1/$5 per 1M tokens it undercuts GLM 5.1, and on millions of tokens that margin decides the monthly bill.

A team with data-privacy or self-hosting needs

GLM 5.1

Open weights let you run it on your own hardware; Claude Haiku 4.5 is API-only.

Anyone whose priority is fastest claude model

Claude Haiku 4.5

It is specifically built for that.

Anyone whose priority is long-horizon autonomous agentic engineering (up to 8-hour runs)

GLM 5.1

That is its strongest area.

An enterprise with regional data-residency rules

Claude Haiku 4.5 or GLM 5.1

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

Claude Haiku 4.5: where it fits

Anthropic's fastest, most compact model — built for speed and volume. Released October 15, 2025 by Anthropic, it is built for fastest Claude model, low-latency, high-volume API calls, real-time interactions, and cheapest Claude tier.

Its trade-offs are real: smallest context in the family (200K), and not for deep reasoning. At $1 in / $5 out per million tokens, it sits in the budget price band.

GLM 5.1: where it fits

An open-weight (MIT) Chinese coding model built for long-horizon agentic engineering, topping SWE-Bench Pro at launch while running autonomously for up to 8 hours. Released April 7, 2026 by Z.ai, it is built for long-horizon autonomous agentic engineering (up to 8-hour runs), state-of-the-art open-weight coding (topped SWE-Bench Pro at launch), sustained tool use across thousands of calls, and self-hostable under a permissive MIT license.

Its trade-offs: text-only, with no image, audio, or video input, and 754B-parameter MoE demands heavy GPU resources to self-host. At $1.4 in / $4.4 out per million tokens, it sits in the mid price band.

The bottom line for this matchup

The defining split here is open vs. closed. GLM 5.1 gives you weights you control — self-host it, fine-tune it, keep data in-house, pay only for hardware. Claude Haiku 4.5 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 Haiku 4.5 and GLM 5.1 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 Claude Haiku 4.5 or GLM 5.1 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, Claude Haiku 4.5 leans toward fastest claude model while GLM 5.1 leans toward long-horizon autonomous agentic engineering (up to 8-hour runs), and that positioning usually predicts which feels better on your codebase.

Which is cheaper, Claude Haiku 4.5 or GLM 5.1?

GLM 5.1 is open-weight, so self-hosting means no per-token fee (you pay for hardware instead), while Claude Haiku 4.5 is API-metered at $1/$5 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?

Both advertise 200K (~300 pages). Remember advertised ≠ usable: recall typically degrades before the ceiling.

Can I use both Claude Haiku 4.5 and GLM 5.1 together?

Yes — a multi-model platform like LumiChats gives you Claude Haiku 4.5, GLM 5.1 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 Haiku 4.5 or GLM 5.1?

GLM 5.1 — released April 7, 2026, about 6 months after Claude Haiku 4.5.

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.