Claude Fable 5 vs Gemini 3.1 Flash Lite
Anthropic · US | Google · US · Updated June 2026
Quick verdict
Pick Claude Fable 5 for the hardest reasoning and most complex problems or long-horizon, multi-step agentic work. Pick Gemini 3.1 Flash Lite for ultra-low-latency, high-volume production workloads or most cost-efficient gemini 3 model — half the price of gemini 3 flash ($0.25/$1.50 vs $0.50/$3.00 per 1m tokens). On a tight budget at scale, Gemini 3.1 Flash Lite is the value pick.
Claude Fable 5 (Anthropic) and Gemini 3.1 Flash Lite (Google) are two of the models people most often weigh against each other in 2026. Claude Fable 5 is anthropic's top public Mythos-class model and its most capable yet, though tier access was temporarily suspended in June 2026 under a US export-control directive. Gemini 3.1 Flash Lite is google's fastest and most cost-efficient Gemini 3 series model, built for ultra-low-latency, high-volume production workloads at half the price of Gemini 3 Flash. Their biggest split is price, and the breakdown below shows exactly how that plays out for your workload.
Key differences at a glance
- ▸Price: Gemini 3.1 Flash Lite is about 40× cheaper on input ($0.25/$1.5 per 1M tokens vs $10/$50 per 1M tokens) — a large enough gap that at scale it can be the single biggest line item in the decision.
- ▸Context window: both advertise 1M (~1,500 pages). Tie on paper — test on your own long inputs, since usable recall varies by model.
- ▸Recency: Claude Fable 5 is the newer model by about 3 months (released June 9, 2026), usually meaning fresher training data and capabilities.
Side-by-side specs
| Spec | Claude Fable 5 | Gemini 3.1 Flash Lite |
|---|---|---|
| Provider | Anthropic (US) | Google (US) |
| Released | June 9, 2026 | March 3, 2026 |
| Context window | 1M (~1,500 pages) | 1M (~1,500 pages) |
| Price (in/out) | $10/$50 per 1M tokens | $0.25/$1.5 per 1M tokens |
| Open weight? | No — API only | No — API only |
| Modalities | text, image, code | text, image, audio, video |
| SWE-Bench Verified | Not published | Not published |
| MRCR v2 @ 1M | Not published | 12.3% |
Who wins what
The hardest reasoning and most complex problems
Claude Fable 5
Gemini 3.1 Flash Lite is comparatively weak here — lower reasoning and quality ceiling than Gemini 3.1 Pro and the full Gemini 3 Flash tier
Long-horizon, multi-step agentic work
Claude Fable 5
Anthropic's top public Mythos-class model and its most capable yet, though tier access was temporarily suspended in June 2026 under a US export-control directive — and it is the newer of the two.
Frontier-level analysis and research
Claude Fable 5
Claude Fable 5 lists frontier-level analysis and research among its strengths; Gemini 3.1 Flash Lite does not.
Ultra-low-latency, high-volume production workloads
Gemini 3.1 Flash Lite
At $0.25/$1.5 per 1M tokens it undercuts Claude Fable 5 ($10/$50 per 1M tokens), and that gap compounds at volume.
Most cost-efficient Gemini 3 model — half the price of Gemini 3 Flash ($0.25/$1.50 vs $0.50/$3.00 per 1M tokens)
Gemini 3.1 Flash Lite
Claude Fable 5 is comparatively weak here — highest price in the Claude lineup
High-volume agentic and tool-calling loops where cost per call matters
Gemini 3.1 Flash Lite
Google's fastest and most cost-efficient Gemini 3 series model, built for ultra-low-latency, high-volume production workloads at half the price of Gemini 3 Flash — and it runs cheaper at $0.25/$1.5 per 1M tokens.
Lowest cost at scale
Gemini 3.1 Flash Lite
At $0.25/$1.5 per 1M tokens, it is the cheaper of the two — the gap dominates the bill on high-volume workloads.
Which should you pick?
A cost-sensitive startup shipping high volume
→ Gemini 3.1 Flash Lite
At $0.25/$1.5 per 1M tokens it undercuts Claude Fable 5, and on millions of tokens that margin decides the monthly bill.
Anyone whose priority is the hardest reasoning and most complex problems
→ Claude Fable 5
It is specifically built for that.
Anyone whose priority is ultra-low-latency, high-volume production workloads
→ Gemini 3.1 Flash Lite
That is its strongest area.
Claude Fable 5: where it fits
Anthropic's top public Mythos-class model and its most capable yet, though tier access was temporarily suspended in June 2026 under a US export-control directive. Released June 9, 2026 by Anthropic, it is built for the hardest reasoning and most complex problems, long-horizon, multi-step agentic work, frontier-level analysis and research, and work where maximum capability outweighs cost.
Its trade-offs are real: highest price in the Claude lineup, and tier access was temporarily suspended in June 2026 under a US export-control directive. At $10 in / $50 out per million tokens, it sits in the premium price band.
Gemini 3.1 Flash Lite: where it fits
Google's fastest and most cost-efficient Gemini 3 series model, built for ultra-low-latency, high-volume production workloads at half the price of Gemini 3 Flash. Released March 3, 2026 by Google, it is built for ultra-low-latency, high-volume production workloads, most cost-efficient Gemini 3 model — half the price of Gemini 3 Flash ($0.25/$1.50 vs $0.50/$3.00 per 1M tokens), high-volume agentic and tool-calling loops where cost per call matters, and multimodal input across text, image, video, audio, and PDF.
Its trade-offs: lower reasoning and quality ceiling than Gemini 3.1 Pro and the full Gemini 3 Flash tier, sharp long-context degradation — MRCR v2 (8-needle) retrieval falls to ~12% at the full 1M-token window, and closed weights — not downloadable or self-hostable. At $0.25 in / $1.5 out per million tokens, it sits in the budget price band.
The bottom line for this matchup
Claude Fable 5 and Gemini 3.1 Flash Lite overlap enough that the right pick depends on your specific job. Gemini 3.1 Flash Lite costs less per token; and each leads in its own area — Claude Fable 5 for the hardest reasoning and most complex problems, Gemini 3.1 Flash Lite for ultra-low-latency, high-volume production workloads. Rather than crowning one, run the same hard task through both once and let the results decide.
Want both Claude Fable 5 and Gemini 3.1 Flash Lite 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 pricingFrequently asked questions
Is Claude Fable 5 or Gemini 3.1 Flash Lite 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 Fable 5 leans toward the hardest reasoning and most complex problems while Gemini 3.1 Flash Lite leans toward ultra-low-latency, high-volume production workloads, and that positioning usually predicts which feels better on your codebase.
Which is cheaper, Claude Fable 5 or Gemini 3.1 Flash Lite?
Gemini 3.1 Flash Lite is cheaper — $10/$50 per 1M tokens vs $0.25/$1.5 per 1M tokens, roughly 40× apart on input.
Which has the bigger context window?
Both advertise 1M (~1,500 pages). Remember advertised ≠ usable: recall typically degrades before the ceiling.
Can I use both Claude Fable 5 and Gemini 3.1 Flash Lite together?
Yes — a multi-model platform like LumiChats gives you Claude Fable 5, Gemini 3.1 Flash Lite 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 Fable 5 or Gemini 3.1 Flash Lite?
Claude Fable 5 — released June 9, 2026, about 3 months after Gemini 3.1 Flash Lite.
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.