Muse Glimmer vs Reka Flash 3.1

Meta · US  |  Reka AI · US · Updated June 2026

Quick verdict

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. Pick Reka Flash 3.1 for a 21b-parameter reasoning model, small enough for local/on-device deployment (a 3.5-bit quantized build exists) or strong base for fine-tuning agentic tasks - notably improved coding since the original flash 3.

Muse Glimmer (Meta) and Reka Flash 3.1 (Reka AI) are two of the models people most often weigh against each other in 2026. 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. Reka Flash 3.1 is reka AI's compact 21B open-weight reasoning model - small enough to run locally, from a team of DeepMind and Meta alumni. Their biggest split is context window, and the breakdown below shows exactly how that plays out for your workload.

Key differences at a glance

Side-by-side specs

SpecMuse GlimmerReka Flash 3.1
ProviderMeta (US) Reka AI (US)
ReleasedAugust 10, 2026 July 2025
Context window128K (~197 pages) 32K (~49 pages)
Price (in/out)Open weight (self-host / free) Open weight (self-host / free)
Open weight?Yes — self-hostable Yes — self-hostable
Modalitiestext, image, code text, code
SWE-Bench VerifiedNot published Not published
MRCR v2 @ 1MNot published Not published

Who wins what

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

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 carries the larger 128K context.

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

Muse Glimmer

Reka Flash 3.1 is comparatively weak here — smaller and less capable overall than flagship frontier models from major labs

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.

A 21B-parameter reasoning model, small enough for local/on-device deployment (a 3.5-bit quantized build exists)

Reka Flash 3.1

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

Strong base for fine-tuning agentic tasks - notably improved coding since the original Flash 3

Reka Flash 3.1

Reka Flash 3.1 lists strong base for fine-tuning agentic tasks - notably improved coding since the original Flash 3 among its strengths; Muse Glimmer does not.

Fully open weights (Apache 2.0) from a frontier-caliber research team

Reka Flash 3.1

Reka Flash 3.1 lists fully open weights (Apache 2.0) from a frontier-caliber research team among its strengths; Muse Glimmer does not.

Largest single-prompt input

Muse Glimmer

Its 128K window is about 4× larger than Reka Flash 3.1's 32K, fitting roughly 197 pages in one prompt.

Which should you pick?

Someone analysing very long documents or codebases

Muse Glimmer

Larger 128K window fits more in one prompt.

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

Muse Glimmer

It is specifically built for that.

Anyone whose priority is a 21b-parameter reasoning model, small enough for local/on-device deployment (a 3.5-bit quantized build exists)

Reka Flash 3.1

That is its strongest area.

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 are real: 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.

Reka Flash 3.1: where it fits

Reka AI's compact 21B open-weight reasoning model - small enough to run locally, from a team of DeepMind and Meta alumni. Released July 2025 by Reka AI, it is built for a 21B-parameter reasoning model, small enough for local/on-device deployment (a 3.5-bit quantized build exists), strong base for fine-tuning agentic tasks - notably improved coding since the original Flash 3, fully open weights (Apache 2.0) from a frontier-caliber research team, and built by alumni from Google DeepMind and Meta's AI labs.

Its trade-offs: a relatively small 32K context window next to million-token frontier models, smaller and less capable overall than flagship frontier models from major labs, and reka's broader roadmap has shifted toward robotics/world models after merging with Moonvalley in June 2026, raising questions about ongoing LLM investment. As an open-weight model, its running cost is your own hardware rather than a per-token fee.

The bottom line for this matchup

Muse Glimmer and Reka Flash 3.1 overlap enough that the right pick depends on your specific job. Muse Glimmer holds the larger context; and each leads in its own area — Muse Glimmer for runs real agentic tasks locally on one consumer gpu - fits 24gb of vram in 4-bit, Reka Flash 3.1 for a 21b-parameter reasoning model, small enough for local/on-device deployment (a 3.5-bit quantized build exists). Rather than crowning one, run the same hard task through both once and let the results decide.

Want both Muse Glimmer and Reka Flash 3.1 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 Muse Glimmer or Reka Flash 3.1 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, Muse Glimmer leans toward runs real agentic tasks locally on one consumer gpu - fits 24gb of vram in 4-bit while Reka Flash 3.1 leans toward a 21b-parameter reasoning model, small enough for local/on-device deployment (a 3.5-bit quantized build exists), and that positioning usually predicts which feels better on your codebase.

Which is cheaper, Muse Glimmer or Reka Flash 3.1?

They are priced almost identically, so cost will not decide between them.

Which has the bigger context window?

Muse Glimmer — 128K vs 32K, about 4× larger. Useful only if the model actually reasons over the full window, which not all do.

Can I use both Muse Glimmer and Reka Flash 3.1 together?

Yes — a multi-model platform like LumiChats gives you Muse Glimmer, Reka Flash 3.1 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, Muse Glimmer or Reka Flash 3.1?

Muse Glimmer — released August 10, 2026, about 14 months after Reka Flash 3.1.

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.