Claude Opus 4.8 vs Muse Glimmer

Anthropic · US  |  Meta · US · Updated June 2026

Quick verdict

Pick Claude Opus 4.8 for agentic coding and multi-file debugging or long autonomous tasks. 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 Opus 4.8 if you want a managed API.

Claude Opus 4.8 (Anthropic) and Muse Glimmer (Meta) are two of the models people most often weigh against each other in 2026. Claude Opus 4.8 is the agentic-coding and judgment leader — highest SWE-Bench Pro score ever recorded at launch. 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 Opus 4.8Muse Glimmer
ProviderAnthropic (US) Meta (US)
ReleasedMay 28, 2026 August 10, 2026
Context window1M (~1,500 pages) 128K (~197 pages)
Price (in/out)$5/$25 per 1M tokens Open weight (self-host / free)
Open weight?No — API only Yes — self-hostable
Modalitiestext, image, code text, image, code
SWE-Bench Verified88.6% Not published
MRCR v2 @ 1MNot published Not published

Who wins what

Agentic coding and multi-file debugging

Claude Opus 4.8

The agentic-coding and judgment leader — highest SWE-Bench Pro score ever recorded at launch — and it carries the larger 1M context.

Long autonomous tasks

Claude Opus 4.8

Its 1M window holds about 7.6× more than Muse Glimmer's 128K in a single prompt.

Honest uncertainty flagging

Claude Opus 4.8

Claude Opus 4.8 lists honest uncertainty flagging among its strengths; Muse Glimmer does not.

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 Opus 4.8 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 Opus 4.8 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 Opus 4.8's $5/$25 per 1M tokens.

Largest single-prompt input

Claude Opus 4.8

Its 1M window is about 7.6× larger than Muse Glimmer's 128K, fitting roughly 1,500 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 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

Muse Glimmer

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

Muse Glimmer

That is its strongest area.

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.

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 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 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 Opus 4.8 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 Opus 4.8 leans toward agentic coding and multi-file debugging 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 Opus 4.8 or Muse Glimmer?

Muse Glimmer 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 128K, about 7.6× 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 Muse Glimmer together?

Yes — a multi-model platform like LumiChats gives you Claude Opus 4.8, 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 Opus 4.8 or Muse Glimmer?

Muse Glimmer — released August 10, 2026, about 2 months after Claude Opus 4.8.

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.