Is Claude Mythos 5.1 Down?

Quickest ways to check the current status of red.anthropic.com plus recent known issues and working alternatives if it's out.

Last editorial review: 2026-09-05

How to check right now

Step 1 -- Load the site
Open red.anthropic.com→

The simplest check. If it loads and you can log in, the tool is up for you.

Step 2 -- Crowdsourced reports
DownDetector: Claude Mythos 5.1→

User-reported outages aggregated across regions. Good signal for partial or regional outages.

Step 3 -- Live social
Search X for “Claude Mythos 5.1down” →

Live tweets from other users. Fastest signal for a fresh outage -- often beats status pages by 10-20 minutes.

Step 4 -- Official status page
Find Claude Mythos 5.1's status page →

Most vendors publish a status page at status.[domain] or on Statuspage.io. Google-search to find the current URL.

Known issues we've tracked

MYTHOS 5.1 SHIPS -- AND ANTHROPIC NOW SAYS IN WRITING THAT MYTHOS AND FABLE ARE THE SAME MODEL (2026-09-01, vendor-primary): Anthropic launched **Claude Mythos 5.1** alongside the generally-available **Claude Fable 5.1**, and stated the relationship explicitly for the first time: '**Claude Fable 5.1 and Claude Mythos 5.1 are the same model, but with different levels of safeguards. Fable 5.1 is generally available, while Mythos 5.1 is available only through our trusted access programs; its safeguards are specifically designed to support work in cybersecurity and the life sciences.**' **THIS RESOLVES WHAT THIS PAGE HAS HAD TO INFER SINCE JUNE.** The Mythos line is not a separate, more capable model -- it is the same weights with a looser safeguard configuration, and Anthropic has now published the quantitative gap. **THE MEASURED SAFEGUARD TAX, FOR THE FIRST TIME:** on Terminal-Bench 4.0, Mythos 5.1 scores **60.9%** against Fable 5.1's **55.8%**. Anthropic is unusually direct that this five-point spread is **not capability**: 'the gap between them reflects the tasks on which our earlier, less precise cyber safeguards intervened. With the improvements we're making to these safeguards today, we expect the difference between the models to be much smaller.' **So the headline reason to want Mythos access is shrinking by Anthropic's own account** -- the 5.1 cycle narrows rather than widens the Fable/Mythos gap, because the fix was applied to the safeguards rather than to the model. **WHAT ACTUALLY CHANGES ACCESS:** cybersecurity safeguards now produce **60% fewer false positives**, and Anthropic says **Fable 5.1 -- the public model -- can now be used to discover software vulnerabilities, though not to develop exploits for them.** That is capability moving out of the gated tier and into the general one. For biology, Anthropic has established an access program **developed in partnership with the US government** to reach Mythos 5.1's advanced biology capabilities, with enrollment to 'open for scientists soon' -- still gated, but a different and more formal gate than the Project Glasswing arrangement this page has tracked. **PRICING IS IDENTICAL TO FABLE 5.1** and is published on the public rate card: $10/MTok input, $12.50 5-minute cache write, $20 1-hour cache write, **$0.25/MTok cache hits** (a 0.025x multiplier, versus 0.1x on every other Claude model), $50/MTok output; Batch $5/$25. Mythos 5.1 is listed as 'limited availability' via anthropic.com/glasswing. **The practical read: if you were pursuing Mythos access purely for benchmark headroom, the case is weaker than it was in June; if you were pursuing it for cyber or life-sciences scope, the gate is still there but the public model now covers vulnerability discovery.**
2026-09-01•Anthropic (anthropic.com/claude-fable-and-mythos-5-1 -- post is at the site ROOT, not under /news/) + platform.claude.com/docs/en/about-claude/pricing.md -- both fetched 2026-09-05 via curl with browser UA
PARTIALLY RESTORED (2026-07-01): The US government **lifted the export controls on June 30**. Anthropic redeployed the public **Fable 5 globally on July 1**, but **Mythos 5 came back only partially** -- 'restored access to Mythos 5 for a set of US organizations, following the US government's approval.' Anthropic says it is continuing efforts to 'expand access to the broader set of domestic and international partners in the Glasswing program,' so non-US and many international Glasswing partners may still be waiting. The re-launch shipped a new safety classifier that blocks the reported jailbreak technique in >99% of cases. Net: Mythos 5 is available again, but on a narrower, government-approved US footprint than before the suspension.
2026-07-01•Anthropic (anthropic.com/news/redeploying-fable-5), CNBC (2026-06-30)
MYTHOS PREVIEW RETIRED (2026-06-30): Per Anthropic's deprecations page, **Claude Mythos Preview reached its retirement date on June 30, 2026** -- Glasswing partners still on the Preview snapshot must now use `claude-mythos-5`. With Fable 5 public and Mythos 5 live, the Preview era is formally closed.
2026-06-30•Anthropic model deprecations page (platform.claude.com/docs/en/about-claude/model-deprecations)
ACCESS SUSPENDED BY US GOVERNMENT (2026-06-12; RESOLVED 2026-07-01 -- see restoration entry above): A US government export-control directive ordered Anthropic to **suspend all access to Claude Mythos 5 and Claude Fable 5** for any foreign national (inside or outside the US, including foreign-national Anthropic employees). To comply, Anthropic **disabled both models for all customers** -- including, per the directive's scope, Project Glasswing partners. Access to all other Anthropic models is unaffected. The Commerce Department acted after another company claimed it had 'jailbroken' Mythos, raising national-security concerns; Anthropic disagrees and met with the Trump administration on 2026-06-15 to contest the order. This is the first frontier model pulled from access by US-government directive -- a landmark moment for AI export control and the open-vs-closed debate (CNBC framed it as 'a big moment for open-source AI'). Watch for restoration or appeal terms.
2026-06-12•Anthropic (anthropic.com/news/fable-mythos-access), CNBC (2026-06-12, 2026-06-15, 2026-06-16), TechCrunch, Axios
RETIREMENT DATE SET (verified 2026-06-11): **Claude Mythos Preview retires June 30, 2026** per Anthropic's deprecations page -- Glasswing partners still on the Preview snapshot must migrate to claude-mythos-5 before then. With Fable 5 public and Mythos 5 live, the Preview era formally closes out at the end of the month
2026-06-11•Anthropic model deprecations page (platform.claude.com/docs/en/about-claude/model-deprecations)
MODEL LAUNCH (2026-06-09): **Claude Mythos 5** replaces Mythos Preview as the Glasswing-track model -- same underlying model as the publicly available Claude Fable 5, with safeguards lifted in certain areas for vetted partners. Existing Mythos Preview users upgrade immediately. Anthropic simultaneously made the Mythos class public for the first time via Fable 5 ($10/$50 per 1M, plan-included through 6/22), with classifier fallback to Opus 4.8 on cybersecurity, bio/chem, and distillation-attempt requests. All Mythos-class traffic now carries mandatory 30-day retention, overriding zero-data-retention agreements (not used for training)
2026-06-09•Anthropic news (anthropic.com/news/claude-fable-5-mythos-5), TechCrunch, CNBC

Issues here are sourced from our editorial sweeps, not real-time telemetry. Newer issues may exist.

What to use if Claude Mythos 5.1 is down

Top AIToolTier-ranked alternatives in the same category, ordered by our overall score.

A

Muse Spark (Meta)

8.8

Meta's frontier model line from its Superintelligence Lab -- Muse Spark 1.1 (2026-07-09) adds substantially better coding, 1M-token multi-agent orchestration, and Meta's first paid developer API (Meta Model API, public preview)

A

Claude (Anthropic)

8.5

Anthropic's flagship LLM family. **Claude Opus 5 launched 2026-07-24** and is now the default model on Claude Max and the strongest model on Claude Pro -- same $5/$25 per 1M as Opus 4.8, but Anthropic says it lands within 0.5% of Fable 5 on CursorBench at half the cost. **Sonnet 5's $2/$10 per 1M is now permanent** -- Anthropic cancelled the 2026-09-01 rise to $3/$15 and made the launch rate standard -- and it stays the default on Free/Pro. **Claude Fable 5.1 and Mythos 5.1 launched 2026-09-01** and now top the range -- same $10/$50 per 1M as Fable 5, with the saving delivered entirely through a 4x cheaper cache read ($1 -> $0.25/MTok), so it is 25-45% cheaper only if your workload reuses cached context. **From 2026-08-14 future Claude models watermark their text output globally** (SynthID-Text; no extra tokens, no price or speed change, no identifying information -- detector API not shipped yet), and the **legacy Workbench plus the experimental prompt-tools APIs retired 2026-08-17**

A

Gemini (Google)

8.3

Google's LLM with deep Google Workspace integration, 2M token context window, and native code execution -- **Gemini 3.8 Flash launched 2026-09-02** -- the third Flash release in six weeks -- at the SAME $0.75/$3.75 per 1M intro rate as 3.7 Flash and, critically, **on the same 2026-12-31 expiry** (then $1.50/$7.50), so the discount window did not reset. HLE-Verified 54.9%; Google warns it uses more tokens per task because it 'works harder', so cost per task can rise at an unchanged rate. **Gemini 3.8 Flash Cyber** is trusted-defenders-only via the new **Fairwind Program**. Gemini 3.7 Flash (2026-08-13) remains fully supported for efficiency-first work. Gemini 3.5 Pro STILL delayed and partner-testing-only (Bloomberg, 7/16 -- coding shortfalls, no ship date), so Flash keeps shipping while the Pro line stalls. Gemini 4 pre-training underway. **Two new models in Aug 2026: Gemini 3.5 Transcribe (2026-08-26) speech-to-text and Gemini Omni 1.1 Flash (2026-08-27) production video with 40s scene extension, start/end frames and 4K** -- neither shipped with a public rate card

A

MiMo (Xiaomi)

8.3

Xiaomi's MiMo-V2.5 family launched 2026-04-22 -- Pro (1T total / 42B active MoE, 1M context, native vision+audio reasoning), Multimodal base, TTS (3 sub-models: base, VoiceDesign, VoiceClone), and ASR (open-source, English + Chinese + major dialects). Full voice pipeline for the agent era. Extra-charge 1M-context tier removed at launch

A

Hunyuan 3 (Tencent Hy3)

8.1

Tencent's Hy3 reached GA 2026-07-06 (upgraded from the April preview) -- 295B total / 21B active MoE, 256K context, now Apache 2.0 open weights on HuggingFace + ModelScope with the EU/UK/South Korea restriction lifted. ~90% agent-task completion on Tencent's internal apps; API via Tencent Cloud TokenHub. Integrated into Yuanbao, WeChat, QQ

About Claude Mythos 5.1

Tier C (6.5/10). Anthropic's trusted-access frontier model. **Mythos 5.1 launched 2026-09-01** alongside Fable 5.1, and Anthropic now states outright that they are **the same model with different safeguards** -- the 5.1-cycle gap is 60.9% vs 55.8% on Terminal-Bench 4.0, which Anthropic attributes to safeguard interventions rather than capability and expects to shrink. Originally launched June 9, 2026 alongside Claude Fable 5. Suspended June 12 by a US export-control order, then PARTIALLY RESTORED July 1, 2026 (US government lifted controls June 30): Mythos 5 is back for a set of US organizations with government approval, while Anthropic works to re-expand the broader Glasswing program. Public Fable 5 returned globally the same day. Gated to Project Glasswing orgs + select biology researchers.

Read the full Claude Mythos 5.1review →