Claude Sonnet 4.5 vs Muse Glimmer

Anthropic · US  |  Meta · US · Updated June 2026

Quick verdict

Pick Claude Sonnet 4.5 for agentic coding — 77.2% on swe-bench verified, the best score any model had posted at its launch or computer use and gui automation (61.4% osworld at launch). Pick Muse Glimmer for runs real agentic tasks locally on one consumer gpu - fits 24gb of vram in 4-bit or open weights (apache 2.0), free to self-host and offline-capable - data never leaves your machine. Choose Muse Glimmer if you need self-hosting or data privacy; Claude Sonnet 4.5 if you want a managed API.

Claude Sonnet 4.5 (Anthropic) and Muse Glimmer (Meta) are two of the models people most often weigh against each other in 2026. Claude Sonnet 4.5 is september 2025's coding state of the art at $3/$15 — still supported, but 200K-capped and twice superseded. Muse Glimmer is meta's open ~30B agentic model - runs tool-using AI agents locally on a single consumer GPU, offline and free, though it trails frontier cloud models. 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 Sonnet 4.5Muse Glimmer
ProviderAnthropic (US) Meta (US)
ReleasedSeptember 29, 2025 August 10, 2026
Context window200K (~300 pages) 128K (~197 pages)
Price (in/out)$3/$15 per 1M tokens Open weight (self-host / free)
Open weight?No — API only Yes — self-hostable
Modalitiestext, image, code text, image, code
SWE-Bench Verified77.2% Not published
MRCR v2 @ 1MNot published Not published

Who wins what

Agentic coding — 77.2% on SWE-Bench Verified, the best score any model had posted at its launch

Claude Sonnet 4.5

Muse Glimmer is comparatively weak here — a distilled ~30B model - ceiling below its closed teacher (Muse Spark) and cloud flagships

Computer use and GUI automation (61.4% OSWorld at launch)

Claude Sonnet 4.5

September 2025's coding state of the art at $3/$15 — still supported, but 200K-capped and twice superseded — and it carries the larger 200K context.

Long-horizon autonomy — Anthropic reported 30+ hours of sustained focus on multi-step tasks

Claude Sonnet 4.5

Its 200K window holds about 1.5× more than Muse Glimmer's 128K in a single prompt.

Runs real agentic tasks locally on one consumer GPU - fits 24GB of VRAM in 4-bit

Muse Glimmer

Open weights make this possible at all — Claude Sonnet 4.5 is API-only, so it cannot leave the vendor's servers.

Open weights (Apache 2.0), free to self-host and offline-capable - data never leaves your machine

Muse Glimmer

Meta's open ~30B agentic model - runs tool-using AI agents locally on a single consumer GPU, offline and free, though it trails frontier cloud models — and its weights are open while Claude Sonnet 4.5 is API-only.

Agentic by design: tool use, coding, file and screenshot reading, multi-step failure recovery

Muse Glimmer

Meta's open ~30B agentic model - runs tool-using AI agents locally on a single consumer GPU, offline and free, though it trails frontier cloud models — and it is the newer of the two.

Lowest cost at scale

Muse Glimmer

Its weights are open, so at volume you pay for your own hardware instead of Claude Sonnet 4.5's $3/$15 per 1M tokens.

Largest single-prompt input

Claude Sonnet 4.5

Its 200K window is about 1.5× larger than Muse Glimmer's 128K, fitting roughly 300 pages in one prompt.

Which should you pick?

A cost-sensitive startup shipping high volume

Muse Glimmer

At Open weight (self-host / free) it undercuts Claude Sonnet 4.5, and on millions of tokens that margin decides the monthly bill.

Someone analysing very long documents or codebases

Claude Sonnet 4.5

Larger 200K window fits more in one prompt.

A team with data-privacy or self-hosting needs

Muse Glimmer

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

Anyone whose priority is agentic coding — 77.2% on swe-bench verified, the best score any model had posted at its launch

Claude Sonnet 4.5

It is specifically built for that.

Anyone whose priority is runs real agentic tasks locally on one consumer gpu - fits 24gb of vram in 4-bit

Muse Glimmer

That is its strongest area.

Claude Sonnet 4.5: where it fits

September 2025's coding state of the art at $3/$15 — still supported, but 200K-capped and twice superseded. Released September 29, 2025 by Anthropic, it is built for agentic coding — 77.2% on SWE-Bench Verified, the best score any model had posted at its launch, computer use and GUI automation (61.4% OSWorld at launch), long-horizon autonomy — Anthropic reported 30+ hours of sustained focus on multi-step tasks, and tracking its own remaining token budget natively, which few models do.

Its trade-offs are real: superseded twice — Sonnet 4.6 and Sonnet 5 match or beat it at the same or lower price, capped at 200K since Anthropic retired its 1M beta in April 2026, while its successors ship 1M as standard, and missing the modern API surface: no adaptive thinking, no effort control, and half the max output of newer Sonnets. At $3 in / $15 out per million tokens, it sits in the mid price band.

Muse Glimmer: where it fits

Meta's open ~30B agentic model - runs tool-using AI agents locally on a single consumer GPU, offline and free, though it trails frontier cloud models. Released August 10, 2026 by Meta, it is built for runs real agentic tasks locally on one consumer GPU - fits 24GB of VRAM in 4-bit, open weights (Apache 2.0), free to self-host and offline-capable - data never leaves your machine, agentic by design: tool use, coding, file and screenshot reading, multi-step failure recovery, and 128K context, text and image input, trained on 100+ languages.

Its trade-offs: a distilled ~30B model - ceiling below its closed teacher (Muse Spark) and cloud flagships, no independent Artificial Analysis intelligence score published yet, published benchmarks (e.g. SWE-Bench Verified 76.0) are Meta's own, and 4-bit quantization to fit consumer GPUs trades away some accuracy. As an open-weight model, its running cost is your own hardware rather than a per-token fee.

The bottom line for this matchup

The defining split here is open vs. closed. Muse Glimmer gives you weights you control — self-host it, fine-tune it, keep data in-house, pay only for hardware. Claude Sonnet 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 Sonnet 4.5 and Muse Glimmer 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 Sonnet 4.5 or Muse Glimmer better for coding?

Public SWE-Bench figures are not available for Muse Glimmer, so the honest test is your own repository — run an identical real bug through both. By design, Claude Sonnet 4.5 leans toward agentic coding — 77.2% on swe-bench verified, the best score any model had posted at its launch while Muse Glimmer leans toward runs real agentic tasks locally on one consumer gpu - fits 24gb of vram in 4-bit, and that positioning usually predicts which feels better on your codebase.

Which is cheaper, Claude Sonnet 4.5 or Muse Glimmer?

Muse Glimmer is open-weight, so self-hosting means no per-token fee (you pay for hardware instead), while Claude Sonnet 4.5 is API-metered at $3/$15 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 Sonnet 4.5 — 200K vs 128K, about 1.5× larger. Useful only if the model actually reasons over the full window, which not all do.

Can I use both Claude Sonnet 4.5 and Muse Glimmer together?

Yes — a multi-model platform like LumiChats gives you Claude Sonnet 4.5, Muse Glimmer 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 Sonnet 4.5 or Muse Glimmer?

Muse Glimmer — released August 10, 2026, about 11 months after Claude Sonnet 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.