Claude Fable 5 wins on coding (100 vs 68) and writing quality. Gemini 3.1 Flash wins on price ($0.5 vs $10/1M input). For most workflows, Claude Fable 5 is the stronger default — superseded by fable 5.1 — still 80.3% swe-bench pro, but 5.1 is better and cheaper to run.
The safest Claude Fable 5 vs Gemini 3.1 Flash default, the cheaper option worth trying first, and the specialist pick — before you read the detail below.
Claude Fable 5 is the strongest answer here for Claude Fable 5 vs Gemini 3.1 Flash — pick it when quality of output matters more than the $10.00/1M/1M input you pay for it.
Gemini 3.1 Flash handles the same job for about 94% less per token. Start here and only move up if the output is not good enough.
Gemini 3.1 Flash is the fastest of these for Claude Fable 5 vs Gemini 3.1 Flash — worth it when latency is what the reader notices, not the last few points of reasoning depth.
Claude Fable 5 leads on coding with a score of 100 vs 68 for Gemini 3.1 Flash.
Gemini 3.1 Flash is cheaper at $0.5/1M input tokens vs $10/1M for Claude Fable 5.
Claude Fable 5 is the stronger default for coding tasks.
Claude Fable 5 is the safer default: it is built for the hardest coding tasks, autonomous multi-step agents, and frontier-grade reasoning, which covers most of what people bring to this comparison.
Switch to Gemini 3.1 Flash when your work is mostly high-volume everyday AI usage where speed and cost both matter; on that narrower brief it is the better tool.
Gemini 3.1 Flash is the more cost-efficient option at $0.5/1M input — Claude Fable 5 costs 20x more per input token, so the gap is worth taking seriously wherever token volume rather than peak quality drives the bill.
Switch the scoring lens to see whether the Claude Fable 5 vs Gemini 3.1 Flash answer changes when cost, speed, or long-document depth leads the decision.
Anthropic / Premium / Sep 3, 2026
New global #1 — 80.3% SWE-Bench Pro, the most capable model generally available.
Ranks models by the broadest mix of coding, writing, research, and long-context usefulness.
You are latency- or cost-sensitive, or your tasks don't need frontier-level reasoning — Opus 4.8 at half the price is plenty.
Where the Claude Fable 5 vs Gemini 3.1 Flash recommendation shifts once you weigh price or latency differently.
New global #1 — 80.3% SWE-Bench Pro, the most capable model generally available.
Best cheap AI for broad day-to-day work — now with 1M context.
List prices and published scores — the numbers this page's pick is built from.
| Model | Input | Output | Est. month | Context | Speed | Coding | Writing | Research |
|---|---|---|---|---|---|---|---|---|
| Claude Fable 5Anthropic | $10.00/1M | $50.00/1M | $200 | 1M tokens | Deliberate | 100 | 98 | 100 |
| Gemini 3.1 FlashGoogle | $0.50/1M | $3.00/1M | $11 | 1M tokens | Very fast | 68 | 75 | 76 |
Scores out of 100 — how we evaluate models. “Est. month” is 10M in / 2M out at list price: a ceiling, no discounts.
Why each one is on the shortlist for Claude Fable 5 vs Gemini 3.1 Flash, what it is genuinely good at, and where we would steer you away from it.
Our pick for Claude Fable 5 vs Gemini 3.1 Flash. It scores 100/100 on the coding axis we weight this page by, and nothing else in this shortlist matches it on output quality.
Anthropic's new Mythos-class flagship and the most capable coding model anyone can use — 80.3% SWE-Bench Pro, an 11-point jump over Opus 4.8. 1M context, 128K output, native parallel subagents. Released June 9, 2026.
You are latency- or cost-sensitive, or your tasks don't need frontier-level reasoning — Opus 4.8 at half the price is plenty.
The strongest coding and reasoning model you can actually use today. 80.3% SWE-Bench Pro is an 11-point leap over Opus 4.8 — the biggest single-release jump of 2026. It costs 2× Opus 4.8, so use it for the hardest agentic and engineering work and keep Opus 4.8 or Sonnet for everyday volume.
Full pricing, benchmark table and release notes on the Claude Fable 5 page.
Where most budgets should land for Claude Fable 5 vs Gemini 3.1 Flash — about 94% less per token than Claude Fable 5, and still 68/100 on the coding axis.
Fast, low-cost model with a 1M token context window — the best budget default for teams running high prompt volumes.
You need premium reasoning depth or the highest coding benchmark scores.
The best all-around budget model for most teams. Faster than its predecessor, cheaper, and with a 1M context window that outclasses every other budget option.
Full pricing, benchmark table and release notes on the Gemini 3.1 Flash page.
UseRightAI recommendations are based on practical decision factors people actually feel in day-to-day use.
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Claude Fable 5 wins on more of the categories we score — coding, research, long context — so it is the better default of the two. Gemini 3.1 Flash is the better pick when your work is mostly high-volume everyday AI usage where speed and cost both matter. Neither is universally "better": Claude Fable 5 is aimed at the hardest coding tasks and autonomous multi-step agents, Gemini 3.1 Flash at high-volume everyday AI usage where speed and cost both matter.
Gemini 3.1 Flash is cheaper at $0.5/1M input and $3/1M output. Claude Fable 5 costs $10/1M input and $50/1M output.
Both Claude Fable 5 and Gemini 3.1 Flash have the same 1M context window.
Claude Fable 5 is better for coding with a score of 100 vs Gemini 3.1 Flash's 68 (out of 100). GPT-6 Astra is the overall coding leader in this directory at 100/100.
Gemini 3.1 Flash is faster with a very fast speed rating (score: 5) vs Claude Fable 5's deliberate rating (score: 2). Speed matters most for interactive and high-throughput work; for batch jobs the Claude Fable 5 latency penalty is usually invisible.
Priced at $10/$50 per 1M tokens — double Opus 4.8 ($5/$25). Deliberate pace; not for latency-sensitive interactive apps. Standard-use safeguards block some high-risk security workloads (use Mythos 5 with partner access). Avoid it if you are starting new work — Claude Fable 5.1 supersedes it at the same base price with 75% cheaper cache reads. Also skip it if you are latency- or cost-sensitive. That is the main case for looking at Gemini 3.1 Flash instead.
Not as sharp as premium models on hard reasoning or complex coding. May need more validation on nuanced technical tasks. Avoid it if you need premium reasoning depth or the highest coding benchmark scores. Against Claude Fable 5 specifically, the gap shows up most on coding (100 vs 68).
Take a moderate workload of 10M input and 2M output tokens a month. Claude Fable 5 runs $200.00 (at $10/1M in and $50/1M out); Gemini 3.1 Flash runs $11.00 (at $0.5/1M in and $3/1M out). That is a $189.00/month difference — Gemini 3.1 Flash is the cheaper of the two at this volume, and the gap scales linearly as you send more. Output tokens dominate the bill on both, so prompt length matters far less than response length.
Yes, and for most teams that beats picking one. A common split is Claude Fable 5 for the hardest coding tasks and autonomous multi-step agents, with Gemini 3.1 Flash handling high-volume everyday AI usage where speed and cost both matter. Routing high-volume, low-stakes calls to Gemini 3.1 Flash at $0.5/1M and reserving Claude Fable 5 for the hard cases is usually the cheapest arrangement that does not cost you quality.