Claude Fable 5 vs Grok 4.5

At a Glance

Compare
Intelligence, Cost, and Efficiency
IntelligenceHigher is better · MM Intelligence v2.5#2 of 4695.6 score · 3/3 sources · complete#25 of 4660.1 score · 3/3 sources · complete
CostLower is better · Published-token output estimate#44 of 44$1.01 per LiveBench case#15 of 44$0.063 per LiveBench case
EfficiencyHigher is better · MM Efficiency v1.5#29 of 3847.8 score · 3/3 sources · complete#11 of 3859.2 score · 3/3 sources · complete
Pricing and Limits
Input priceFrom · USD / 1M tokens$10.00Anthropic · Sep 3, 2026$2.00Xai · Sep 3, 2026
Output priceFrom · USD / 1M tokens$50.00Anthropic · Sep 3, 2026$6.00Xai · Sep 3, 2026
Context windowMaximum documented tokens1,000K500K
Model facts checkedAug 28, 2026View model evidence →Sep 3, 2026View model evidence →

Token prices are the lowest available sourced USD rates; input and output may use different providers. Cost ranking estimates output spend on LiveBench, not a full request bill. Ranking methodology →

Available Benchmarks

All benchmark results →
BenchmarkClaude Fable 5Grok 4.5
ARC-AGI-1verified-v1-ba05d69f6453 · verified_score · leader98.50100% of row best · percent · Claude Fable 5 (XHigh)87.1788% of row best · percent · Grok 4.5 (Medium)
ARC-AGI-2verified-v2-6c676fa3e9af · verified_score · leader89.17100% of row best · percent · Claude Fable 5 (Max)52.6459% of row best · percent · Grok 4.5 (Medium)
LMArena Agent Arenaagent-2026-09-15-d25aabda0010 · outcome_score · leader8.81100% of row best · score · Claude Fable 5 (High); 95% CI [7.56791873, 10.05963763]; sessions 38293; observations 2061291; rank 52.9295% of row best · score · Grok 4.5; 95% CI [1.93207740, 3.90928463]; sessions 38146; observations 1942877; rank 19
LMArena Document Arenadocument-2026-09-13-d25aabda0010 · arena_rating · leader1,496.08100% of row best · rating · claude-fable-5; 95% CI [1488.22135990, 1503.94311259]; votes 8497; rank 51,451.9697% of row best · rating · grok-4.5; 95% CI [1443.26182849, 1460.65626012]; votes 4965; rank 26
LMArena Search Arenasearch-2026-08-24-d25aabda0010 · arena_rating · leader1,230.22100% of row best · rating · claude-fable-5; 95% CI [1222.30895335, 1238.13609545]; votes 41795; rank 51,212.6599% of row best · rating · grok-4.5; 95% CI [1205.78347274, 1219.50889748]; votes 31505; rank 8
LMArena Text Arenatext-2026-09-13-d25aabda0010 · arena_rating · leader1,492.63100% of row best · rating · claude-fable-5; 95% CI [1487.86770992, 1497.38399139]; votes 30057; rank 71,450.1397% of row best · rating · grok-4.5; 95% CI [1445.44268767, 1454.81726995]; votes 30103; rank 45
LMArena Vision Arenavision-2026-09-13-d25aabda0010 · arena_rating · leader1,325.86100% of row best · rating · claude-fable-5; 95% CI [1317.96760009, 1333.76174084]; votes 11304; rank 11,288.5497% of row best · rating · grok-4.5; 95% CI [1280.47745270, 1296.60872281]; votes 8355; rank 24
LiveBench2026-06-25 · overall · leader86.55100% of row best · percent · claude-fable-5-max-effort · 20,255 output tokens / case80.0192% of row best · percent · grok-4.5 · 10,517 output tokens / case
ToneBench2026-09-11-10-task-4ef099199c9c · overall_score · unverified89.06100% of row best · points · Claude Fable 5 (xhigh) · 18,129 output tokens / case82.2392% of row best · points · Grok 4.5 · 2,688 output tokens / case
Overall ResultCounted from the protocol-matched rows above8 benchmark winsOverall lead0 benchmark wins

Third-party benchmark Only like-for-like primary-publisher results are shown; raw scores, relative scores, configuration, and token spend remain visible.

Side-by-Side Facts

FieldClaude Fable 5Grok 4.5
DeveloperAnthropicxAI
FamilyClaude 5Grok 4
ModelClaude Fable 5Grok 4.5
VersionClaude Fable 5Grok 4.5
Lifecycleactiveactive
Released2026-06-092026-07-16
Knowledge cutoffUnknownUnknown
Input modalitiesText, ImageText, Image
Output modalitiesTextText
Context window1,000K500K
Total parametersUnknownUnknown
Active parametersUnknownUnknown
LicenseUnknownUnknown
Open weightsNoNo
API availableYesYes
Self-hostableNoNo
Provider accessAnthropic (Standard), Deepinfra (Standard), Openrouter (Standard)Xai (Standard)
Capabilitieschat, generation, reasoning, toolschat, generation, reasoning, structured_outputs, tools

Claude Fable 5 Capabilities

chatgenerationreasoningtools
Serving providers3
Canonical IDanthropic/claude-fable-5

Grok 4.5 Capabilities

chatgenerationreasoningstructured outputstools
Serving providers1
Canonical IDxai/grok-4.5

Primary Evidence

Sources and Freshness

Questions

Claude Fable 5 vs Grok 4.5 FAQs

Is Claude Fable 5 or Grok 4.5 better for coding?+

This comparison does not currently contain a protocol-matched coding benchmark for both Claude Fable 5 and Grok 4.5, so Model Markets cannot name a coding leader from pricing, context size, or capability labels alone.

Which is cheaper, Claude Fable 5 or Grok 4.5?+

Claude Fable 5 is $10.00 and Grok 4.5 is $2.00 per million tokens, so Grok 4.5 is cheaper on this metric. Claude Fable 5 is $50.00 and Grok 4.5 is $6.00 per million tokens, so Grok 4.5 is cheaper on this metric.

Which has a larger context window, Claude Fable 5 or Grok 4.5?+

Claude Fable 5 has the larger sourced context window. Claude Fable 5 supports 1,000K and Grok 4.5 supports 500K.

Which performs better in benchmarks, Claude Fable 5 or Grok 4.5?+

Claude Fable 5 leads the current overall benchmark count. The result uses 8 protocol-matched benchmarks from 3 publishers; it is not a universal quality score.

Can Claude Fable 5 or Grok 4.5 be self-hosted?+

Both models have the same recorded self-hosting status: unsupported. Claude Fable 5 is not marked open weight; Grok 4.5 is not marked open weight.

Can Claude Fable 5 and Grok 4.5 understand images?+

Claude Fable 5 is documented with image input; Grok 4.5 is documented with image input. This reflects supported input modalities, not vision quality.

Which can generate longer answers, Claude Fable 5 or Grok 4.5?+

Neither has a larger sourced maximum output. Claude Fable 5 is 128K and Grok 4.5 is —.

Do Claude Fable 5 and Grok 4.5 support reasoning and tool use?+

Claude Fable 5: reasoning, tool calling, and image input. Grok 4.5: reasoning, tool calling, and image input. Feature support does not establish relative quality.

Which is available from more inference providers, Claude Fable 5 or Grok 4.5?+

Claude Fable 5 has 3 sourced provider routes; Grok 4.5 has 1, so Claude Fable 5 has broader tracked availability.

Which offers better value, Claude Fable 5 or Grok 4.5?+

There is no universal value winner. Compare the input and output prices above with the matched benchmark result for your workload: cheaper tokens can be offset by different quality, token usage, latency, or provider availability.

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