#156
XA
Grok 1.5
xAI
19.3 LLMBoard
xAI model product
Bringing the next generation of tool-calling agents to the xAI API. Grok-4.1 Fast Reasoning is a high-speed variant optimized for faster inference while maintaining strong reasoning capabilities through thinking tokens.
Updated Aug 10, 2026. Default version: Grok-4.1 Fast Reasoning
Structured fields from the published default version.
This profile uses the latest version under this unique model that has a calculated LLMBoard score. Arena and price are excluded.
No published version under this unique model currently has enough benchmark coverage to calculate a score.
Published benchmark records for the scored version currently unavailable.
No published benchmark result is linked to the scored version.
Preference and agent-evaluation signals from published Arena datasets.
| vision | entity recognition | 22 | 1234.8 | 108 | N/A | |
| vision style control | entity recognition | 24 | 1201.7 | 108 | N/A | |
| text factuality | korean | 32 | 1370.3 | 386 | N/A | |
| text factuality | german | 34 | 1392.2 | 404 | N/A | |
| vision style control | creative writing vision | 38 | 1239.5 | 762 | N/A | |
| vision | humor | 42 | 1234.7 | 445 | N/A | |
| vision style control | humor | 44 | 1224.6 | 445 | N/A | |
| vision | creative writing vision | 46 | 1244.8 | 762 | N/A | |
| text factuality | polish | 48 | 1389.1 | 865 | N/A | |
| text factuality | spanish | 62 | 1402.1 | 861 | N/A | |
| vision | chinese | 62 | 1231.9 | 785 | N/A | |
| text factuality | french | 63 | 1433.5 | 858 | N/A | |
| vision style control | chinese | 64 | 1222.3 | 785 | N/A | |
| vision style control | english | 70 | 1206.4 | 5,196 | N/A | |
| text style control | creative writing | 71 | 1413.7 | 8,694 | N/A | |
| vision | diagram | 71 | 1207.9 | 3,230 | N/A | |
| vision | overall | 72 | 1199.9 | 12,462 | N/A | |
| vision | english | 72 | 1212.3 | 5,196 | N/A | |
| vision style control | diagram | 73 | 1214.9 | 3,230 | N/A | |
| vision style control | overall | 75 | 1195.2 | 12,462 | N/A | |
| vision | ocr | 77 | 1192.5 | 8,692 | N/A | |
| vision style control | ocr | 78 | 1191.8 | 8,692 | N/A | |
| text factuality | industry mathematical | 79 | 1404.3 | 1,726 | N/A | |
| text factuality | math | 79 | 1411.3 | 2,010 | N/A | |
| text style control | spanish | 80 | 1428.3 | 1,429 | N/A | |
| text factuality | creative writing | 81 | 1405.4 | 5,210 | N/A | |
| text style control | polish | 81 | 1423.4 | 1,395 | N/A | |
| vision | homework | 81 | 1172.1 | 1,979 | N/A | |
| text style control | industry entertainment and sports and media | 83 | 1402.8 | 10,798 | N/A | |
| vision style control | homework | 83 | 1170.5 | 1,979 | N/A | |
| text factuality | chinese | 85 | 1436.2 | 1,803 | N/A | |
| text style control | korean | 88 | 1376.6 | 847 | N/A | |
| text style control | non english | 88 | 1416.0 | 30,125 | N/A | |
| text style control | overall | 90 | 1431.0 | 56,402 | N/A | |
| text style control | exclude ties | 90 | 1424.9 | 40,833 | N/A | |
| text style control | english | 91 | 1440.7 | 26,267 | N/A | |
| webdev | webdev-react | 91 | 1221.3 | 1,247 | N/A | |
| text | creative writing | 92 | 1393.2 | 8,694 | N/A | |
| text style control | industry medicine and healthcare | 92 | 1447.5 | 3,650 | N/A | |
| text style control | industry writing and literature and language | 92 | 1407.2 | 12,878 | N/A | |
| text factuality | industry medicine and healthcare | 96 | 1431.6 | 2,185 | N/A | |
| text style control | german | 96 | 1415.6 | 894 | N/A | |
| text | korean | 97 | 1361.9 | 847 | N/A | |
| text | spanish | 97 | 1412.8 | 1,429 | N/A | |
| text factuality | industry entertainment and sports and media | 97 | 1389.9 | 6,723 | N/A | |
| text style control | french | 97 | 1441.6 | 1,331 | N/A | |
| text style control | industry life and physical and social science | 97 | 1446.9 | 9,094 | N/A | |
| text factuality | industry legal and government | 98 | 1410.8 | 2,423 | N/A | |
| text style control | japanese | 98 | 1367.8 | 382 | N/A | |
| text factuality | expert | 99 | 1420.5 | 2,514 | N/A | |
| webdev | overall | 99 | 1240.1 | 5,308 | N/A | |
| webdev | webdev | 99 | 1240.1 | 5,308 | N/A | |
| webdev | webdev-html | 99 | 1252.5 | 4,061 | N/A | |
| text | japanese | 101 | 1347.1 | 382 | N/A | |
| text factuality | russian | 101 | 1390.6 | 3,392 | N/A | |
| text style control | industry software and it services | 102 | 1457.4 | 20,409 | N/A | |
| text factuality | industry writing and literature and language | 103 | 1396.9 | 8,160 | N/A | |
| text style control | chinese | 104 | 1461.0 | 2,883 | N/A | |
| text | polish | 105 | 1397.3 | 1,395 | N/A | |
| text style control | hard prompts | 105 | 1441.7 | 32,466 | N/A | |
| text | german | 106 | 1398.9 | 894 | N/A | |
| text | industry entertainment and sports and media | 106 | 1381.8 | 10,798 | N/A | |
| text style control | industry business and management and financial operations | 106 | 1417.2 | 10,773 | N/A | |
| text style control | math | 106 | 1417.8 | 3,462 | N/A | |
| text style control | expert | 107 | 1439.9 | 4,057 | N/A | |
| text style control | russian | 107 | 1409.6 | 5,965 | N/A | |
| text style control | industry legal and government | 109 | 1426.8 | 4,039 | N/A | |
| text style control | industry mathematical | 109 | 1423.0 | 2,749 | N/A | |
| text style control | hard prompts english | 111 | 1444.3 | 15,960 | N/A | |
| text factuality | industry life and physical and social science | 112 | 1426.0 | 5,517 | N/A | |
| text style control | coding | 112 | 1461.3 | 13,507 | N/A | |
| text factuality | coding | 114 | 1448.0 | 8,840 | N/A | |
| text factuality | multi turn | 114 | 1397.6 | 6,335 | N/A | |
| text | french | 115 | 1415.4 | 1,331 | N/A | |
| text style control | longer query | 115 | 1423.5 | 17,400 | N/A | |
| text | industry writing and literature and language | 116 | 1386.7 | 12,878 | N/A | |
| text factuality | longer query | 116 | 1412.9 | 12,896 | N/A | |
| text factuality | hard prompts english | 117 | 1431.3 | 11,214 | N/A | |
| text factuality | industry business and management and financial operations | 117 | 1392.9 | 6,629 | N/A | |
| text factuality | instruction following | 117 | 1394.6 | 11,740 | N/A | |
| text style control | multi turn | 117 | 1415.7 | 10,178 | N/A | |
| text | industry medicine and healthcare | 118 | 1414.5 | 3,650 | N/A | |
| text factuality | english | 118 | 1424.8 | 25,486 | N/A | |
| text factuality | exclude ties | 118 | 1404.8 | 40,055 | N/A | |
| text style control | instruction following | 118 | 1402.4 | 16,454 | N/A | |
| text | chinese | 119 | 1440.3 | 2,883 | N/A | |
| text | english | 119 | 1417.9 | 26,267 | N/A | |
| text factuality | overall | 120 | 1413.1 | 55,484 | N/A | |
| text factuality | non english | 120 | 1397.7 | 29,427 | N/A | |
| text | overall | 121 | 1408.5 | 56,402 | N/A | |
| text | exclude ties | 121 | 1392.3 | 40,833 | N/A | |
| text | industry life and physical and social science | 121 | 1419.9 | 9,094 | N/A | |
| text factuality | industry software and it services | 121 | 1437.5 | 16,785 | N/A | |
| text | non english | 124 | 1394.2 | 30,125 | N/A | |
| text factuality | hard prompts | 125 | 1428.2 | 31,772 | N/A | |
| text | expert | 127 | 1400.9 | 4,057 | N/A | |
| text | hard prompts | 127 | 1407.9 | 32,466 | N/A | |
| text | industry software and it services | 127 | 1418.1 | 20,409 | N/A | |
| text | math | 127 | 1404.6 | 3,462 | N/A | |
| text | hard prompts english | 130 | 1409.9 | 15,960 | N/A |
Official vendor API PAYG pricing is summarized first. The table then lists individual provider offerings without treating their minimum as the official price.
| Jiekou.AI | grok-4-1-fast-reasoning | global | $0.18 | $0.45 | 2M | |
| Helicone | grok-4-1-fast-reasoning | global | $0.20 | $0.50 | 2M | |
| LLM Gateway | grok-4-1-fast-reasoning | global | $0.20 | $0.50 | 2M | |
| 302.AI | grok-4-1-fast-reasoning | global | $0.20 | $0.50 | 2M | |
| FrogBot | grok-4-1-fast-reasoning | global | $0.20 | $0.50 | 2M | |
| Azure | grok-4-1-fast-reasoning | global | $0.20 | $0.50 | 128K | |
| Vercel AI Gateway | xai/grok-4.1-fast-reasoning | global | $0.20 | $0.50 | 1M |
Official prices use only the vendor's configured official Provider and positive standard USD PAYG rates. Third-party offers remain explicitly labeled.
All published versions linked to this unique model. The score columns identify the version used by the current overall ranking.
| Grok-4.1 Fast Reasoning | N/A | N/A | 2M | 30K | No | Proprietary |
A concise description based on the published model registry.
Bringing the next generation of tool-calling agents to the xAI API. Grok-4.1 Fast Reasoning is a high-speed variant optimized for faster inference while maintaining strong reasoning capabilities through thinking tokens.
Use the benchmark, Arena and pricing sections above as separate evidence. A missing field means the current data snapshot does not support that claim.
Data snapshot: 2026-08-07. Editorial model content is not available in the backend.
Recommendations prioritize the same model type and family, then the closest published LLMBoard score.
Common questions about Grok 4.1 Fast Reasoning.
Grok 4.1 Fast Reasoning's default version was released on Nov 17, 2025.
No official standard PAYG price is currently available for Grok 4.1 Fast Reasoning. The lowest tracked third-party offer starts at $0.18 input and $0.45 output via Jiekou.AI.
Grok 4.1 Fast Reasoning is published under xAI in the model registry.
The default version has a 2M token context window.
No. The default version is not marked as having publicly available weights.
8 published provider offerings are linked to the default version.
No nearby ranked alternatives are currently available.