Claude Haiku 5.5 vs GLM 5.1

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

Quick verdict

Pick Claude Haiku 5.5 for 5x the context window of haiku 4.5 (1m vs 200k tokens) and double the max output (128k vs 64k) or first haiku-class model with an adjustable 'effort' setting to trade off cost, latency, and intelligence. 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 5.5 if you want a managed API.

Claude Haiku 5.5 (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 5.5 is anthropic's October 7, 2026 small-model refresh — a 1M-token context window (up from 200K) at roughly 75% lower average cost than Haiku 4.5, priced at $0.10/$0.50 per million tokens. 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, context window and open vs. closed weights — each quantified below from the models' real specs.

Key differences at a glance

Side-by-side specs

SpecClaude Haiku 5.5GLM 5.1
ProviderAnthropic (US) Z.ai (China)
ReleasedOctober 7, 2026 April 7, 2026
Context window1M tokens (~1,500 pages) 200K (~300 pages)
Price (in/out)$0.1/$0.5 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

5x the context window of Haiku 4.5 (1M vs 200K tokens) and double the max output (128K vs 64K)

Claude Haiku 5.5

Its 1M tokens window holds about 5× more than GLM 5.1's 200K in a single prompt.

First Haiku-class model with an adjustable 'effort' setting to trade off cost, latency, and intelligence

Claude Haiku 5.5

At $0.1/$0.5 per 1M tokens it undercuts GLM 5.1 ($1.4/$4.4 per 1M tokens), and that gap compounds at volume.

Anthropic's cheapest small model yet — runs about 75% cheaper on average than Haiku 4.5

Claude Haiku 5.5

Anthropic's October 7, 2026 small-model refresh — a 1M-token context window (up from 200K) at roughly 75% lower average cost than Haiku 4.5, priced at $0.10/$0.50 per million tokens — and it runs cheaper at $0.1/$0.5 per 1M tokens.

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

GLM 5.1

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 — and its weights are open while Claude Haiku 5.5 is API-only.

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

GLM 5.1

Open weights make this possible at all — Claude Haiku 5.5 is API-only, so it cannot leave the vendor's servers.

Sustained tool use across thousands of calls

GLM 5.1

GLM 5.1 lists sustained tool use across thousands of calls among its strengths; Claude Haiku 5.5 does not.

Lowest cost at scale

Claude Haiku 5.5

At $0.1/$0.5 per 1M tokens, it is the cheaper of the two — the gap dominates the bill on high-volume workloads.

Largest single-prompt input

Claude Haiku 5.5

Its 1M tokens window is about 5× larger than GLM 5.1's 200K, fitting roughly 1,500 pages in one prompt.

Which should you pick?

A cost-sensitive startup shipping high volume

→ Claude Haiku 5.5

At $0.1/$0.5 per 1M tokens it undercuts GLM 5.1, and on millions of tokens that margin decides the monthly bill.

Someone analysing very long documents or codebases

→ Claude Haiku 5.5

Larger 1M tokens window fits more in one prompt.

A team with data-privacy or self-hosting needs

→ GLM 5.1

Open weights let you run it on your own hardware; Claude Haiku 5.5 is API-only.

Anyone whose priority is 5x the context window of haiku 4.5 (1m vs 200k tokens) and double the max output (128k vs 64k)

→ Claude Haiku 5.5

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 5.5 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 5.5: where it fits

Anthropic's October 7, 2026 small-model refresh — a 1M-token context window (up from 200K) at roughly 75% lower average cost than Haiku 4.5, priced at $0.10/$0.50 per million tokens. Released October 7, 2026 by Anthropic, it is built for 5x the context window of Haiku 4.5 (1M vs 200K tokens) and double the max output (128K vs 64K), first Haiku-class model with an adjustable 'effort' setting to trade off cost, latency, and intelligence, anthropic's cheapest small model yet — runs about 75% cheaper on average than Haiku 4.5, and over-refuses benign requests only 0.17% of the time on the API, down from Haiku 4.5's 0.44%.

Its trade-offs are real: pricing jumps roughly 5x beyond 100K-token prompts ($0.50/$2.50 per million vs the headline $0.10/$0.50), extended thinking can no longer be fully disabled — only dialed between low, medium, and high effort, and as the smallest tier, trails both Sonnet 5.5 and Opus 5.5 on hard reasoning and open-ended work. At $0.1 in / $0.5 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 5.5 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 5.5 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 5.5 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 5.5 leans toward 5x the context window of haiku 4.5 (1m vs 200k tokens) and double the max output (128k vs 64k) 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 5.5 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 5.5 is API-metered at $0.1/$0.5 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?

Claude Haiku 5.5 — 1M tokens 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 Haiku 5.5 and GLM 5.1 together?

Yes — a multi-model platform like LumiChats gives you Claude Haiku 5.5, 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 5.5 or GLM 5.1?

Claude Haiku 5.5 — released October 7, 2026, about 6 months after GLM 5.1.

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.