GPT-5 vs Grok 4 Fast
Wins 6 of 7 areas
Coding · Reasoning · Facts · Images and charts · Long documents · Following instructions
Wins 0 of 7 areas
—
GPT-5 is the stronger all-rounder.Grok 4 Fast is cheaper.
Scores updated · 29 tests both models report · How we compare
Where each one wins
Tests won in each of the seven areas where both have results. Each piece is one test, so a longer bar means more evidence; grey means the two scored within a point of each other.
- ReasoningHard problems that need careful thinking30GPT-53 of 4 tests · 1 tie
- CodingWriting and fixing software21GPT-52 of 3 tests
- FactsGetting facts right instead of making them up21GPT-52 of 3 tests
- Images and chartsUnderstanding pictures, charts and video10GPT-51 of 1 test
- Long documentsFinding answers in very long texts10GPT-51 of 1 test
- Following instructionsDoing exactly what it is asked10GPT-51 of 1 test
- AgentsCarrying out multi-step tasks on its own11Even1 each
Images and charts, long documents and following instructions rest on a single test each.
What it costs
Prices per million tokens, roughly 750,000 words. The bars show the cost of a million tokens read plus a million written.
Grok 4 Fast costs 94% less for the same work.
The biggest differences
The three tests each model wins by the widest margin. Scores are out of 100.
Where GPT-5 pulls ahead
- Follows unfamiliar, precisely checkable instructionsIFBench+22.6points ahead
- Answers hard knowledge questions correctlyAA-Omniscience · Accuracy+17.5points ahead
- Hard command-line tasks in a real terminalTerminal-Bench Hard+13.7points ahead
Where Grok 4 Fast pulls ahead
- Avoids making up answers it doesn't knowAA-Omniscience · Non-hallucination+13.9points ahead
- Real work tasks from 44 professionsGDPVal+4.7points ahead
- Code for real scientific research problemsSciCode+1.3points ahead
Every test, side by side
All 29 tests both models report. The winning score is in its model's colour; marks a score checked independently.
CodingGPT-5
- LMArena · WebDevGPT-5 by 259 rating points14181159+259 rating
- Terminal-Bench HardGPT-5 by 13.732.618.9+13.7
- SciCodeGrok 4 Fast by 1.342.944.2+1.3
ReasoningGPT-5
- Humanity's Last ExamGPT-5 by 9.428.519.1+9.4
- ARC-AGI-2GPT-5 by 4.69.95.3+4.6
- CritPtGPT-5 by 2.85.72.9+2.8
- GPQA Diamondtie85.484.7tie
FactsGPT-5
- AA-Omniscience · AccuracyGPT-5 by 17.540.322.8+17.5
- AA-Omniscience · Non-hallucinationGrok 4 Fast by 13.917.831.7+13.9
- Vectara HHEM hallucination ratelower is betterGPT-5 by 5.115.120.2+5.1
Other results14 tests, not counted
Tests outside the eight areas. They are not counted above: several are summary scores built from other tests, or the same test under another name.
- AA-OmniscienceGPT-5 by 21.2-8.7-29.9+21.2
- τ²-Bench Telecom (AA run)GPT-5 by 1984.865.8+19
- BrowseComp-ZHGPT-5 by 186345+18
- ARC-AGI-1GPT-5 by 17.265.748.5+17.2
- AA Agentic IndexGrok 4 Fast by 1326.539.5+13
- Artificial Analysis Coding IndexGPT-5 by 10.437.827.4+10.4
- LiveCodeBench (Jan-May)GPT-5 by 7.886.879+7.8
- AA IntelligenceGPT-5 by 5.12317.9+5.1
- vectara_factual_consistencyGPT-5 by 5.184.979.8+5.1
- LiveCodeBenchGPT-5 by 3.583.580+3.5
- AIME 2025GPT-5 by 2.694.692+2.6
- vectara_avg_summary_lengthGrok 4 Fast by 11.2 rating points162.7173.9+11.2 rating
- vectara_answer_ratetie99.999.5tie
- HMMT 2025tie93.393.3tie
Questions people ask
Which is better, GPT-5 or Grok 4 Fast?
GPT-5 wins six of the seven areas where both have results: coding, reasoning, facts, images and charts, long documents and following instructions. Grok 4 Fast wins none, but costs 94% less. They are level on agents.
Which is better for coding?
GPT-5. It wins 2 of the 3 coding tests both models report; Grok 4 Fast wins 1.
Which is cheaper?
GPT-5 costs $1.25 per million input tokens and $10.00 per million output tokens; Grok 4 Fast costs $0.20 and $0.50. That makes Grok 4 Fast about 94% cheaper for the same work.
How do you compare the two?
We use the 29 benchmark tests both models have published scores on. The verdict counts the 15 tests in the eight capability areas, and a gap under one point (ten on rating-style scales) counts as a tie. The other 14 are listed but not counted, because several are summary scores or repeat a test. Each score is the one shown on the model's own page.