Both are xAI models. Grok Code Fast 1 is the newer, generally stronger default; reach for Grok 4 when a specific cost or latency profile matters more than the latest capabilities.
Grok 4 and Grok Code Fast 1 are both xAI models, so the real question is not which lab to trust but which tier fits your workload and budget. Grok 4 is xAI's 2M-context model with live data access and strong reasoning chops. Grok Code Fast 1 is xAI's speed-tier coding model at $0.20/$1.50 with a 256K window — cheap, fast agentic code over frontier quality. Since both come from the same lab, the comparison below focuses on the tier-and-cost trade-offs that actually separate them.
Key differences
Price: Grok Code Fast 1 is about 15× cheaper on input ($0.2/$1.5 per 1M tokens vs $3/$15 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 256K (~384 pages). Tie on paper — test on your own long inputs, since usable recall varies by model.
Recency: Grok Code Fast 1 is the newer model by about 50 days (released August 28, 2025), usually meaning fresher training data and capabilities.
Specifications
Spec
Grok 4
Grok Code Fast 1
Provider
xAI (US)
xAI (US)
Released
July 9, 2025
August 28, 2025
Context window
256K (~384 pages)
256K (~384 pages)
Price (in/out)
$3/$15 per 1M tokens
$0.2/$1.5 per 1M tokens
Open weight?
No — API only
No — API only
Modalities
text, image, code
text, code
SWE-Bench Verified
Not published
Not published
MRCR v2 @ 1M
Not published
Not published
Who wins what
256K context with native tool use: Grok 4 — Grok 4 lists 256K context with native tool use among its strengths; Grok Code Fast 1 does not.
Real-time data via X integration: Grok 4 — Grok 4 lists real-time data via X integration among its strengths; Grok Code Fast 1 does not.
Strong academic reasoning: Grok 4 — Grok 4 lists strong academic reasoning among its strengths; Grok Code Fast 1 does not.
Fast, cheap agentic coding at $0.20/$1.50: Grok Code Fast 1 — At $0.2/$1.5 per 1M tokens it undercuts Grok 4 ($3/$15 per 1M tokens), and that gap compounds at volume.
Low-latency code generation and terminal tasks: Grok Code Fast 1 — XAI's speed-tier coding model at $0.20/$1.50 with a 256K window — cheap, fast agentic code over frontier quality — and it runs cheaper at $0.2/$1.5 per 1M tokens.
High-volume coding pipelines where speed beats peak quality: Grok Code Fast 1 — XAI's speed-tier coding model at $0.20/$1.50 with a 256K window — cheap, fast agentic code over frontier quality — and it is the newer of the two.
Lowest cost at scale: Grok Code Fast 1 — At $0.2/$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: Grok Code Fast 1 — At $0.2/$1.5 per 1M tokens it undercuts Grok 4, and on millions of tokens that margin decides the monthly bill.
Anyone whose priority is 256k context with native tool use: Grok 4 — It is specifically built for that.
Anyone whose priority is fast, cheap agentic coding at $0.20/$1.50: Grok Code Fast 1 — That is its strongest area.
Grok 4: where it fits
XAI's 2M-context model with live data access and strong reasoning chops. Released July 9, 2025 by xAI, it is built for 256K context with native tool use, real-time data via X integration, strong academic reasoning, and no long-context surcharge.
Its trade-offs are real: smaller ecosystem than OpenAI/Google, and less independent benchmark coverage. At $3 in / $15 out per million tokens, it sits in the mid price band.
Grok Code Fast 1: where it fits
XAI's speed-tier coding model at $0.20/$1.50 with a 256K window — cheap, fast agentic code over frontier quality. Released August 28, 2025 by xAI, it is built for fast, cheap agentic coding at $0.20/$1.50, low-latency code generation and terminal tasks, high-volume coding pipelines where speed beats peak quality, and a 256K window sized for real codebases.
Its trade-offs: text and code only — no image, audio or video input, xAI did not publish a SWE-Bench Verified score, a speed-tier coding model, not a frontier reasoner, and narrow focus — built for code, not general knowledge work. At $0.2 in / $1.5 out per million tokens, it sits in the budget price band.
The bottom line for this matchup
Because Grok 4 and Grok Code Fast 1 come from the same lab (xAI), they share the same training philosophy and ecosystem — the decision is purely tier vs. cost. Grok Code Fast 1 is the more capable, more recent option; the other earns its place only when its price or latency profile fits a specific job better. Most teams should default to Grok Code Fast 1 and drop down only with a concrete reason.
Frequently asked questions
Is Grok 4 or Grok Code Fast 1 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, Grok 4 leans toward 256k context with native tool use while Grok Code Fast 1 leans toward fast, cheap agentic coding at $0.20/$1.50, and that positioning usually predicts which feels better on your codebase.
Which is cheaper, Grok 4 or Grok Code Fast 1?
Grok Code Fast 1 is cheaper — $3/$15 per 1M tokens vs $0.2/$1.5 per 1M tokens, roughly 15× apart on input.
Which has the bigger context window?
Both advertise 256K (~384 pages). Remember advertised ≠ usable: recall typically degrades before the ceiling.
Should I upgrade from Grok 4 to Grok Code Fast 1?
Since both are xAI models, the newer one (Grok Code Fast 1) is usually the better default unless you need a specific cost or latency profile from the other.
Which is newer, Grok 4 or Grok Code Fast 1?
Grok Code Fast 1 — released August 28, 2025, about 50 days after Grok 4.
Grok 4 vs Grok Code Fast 1
xAI · US | xAI · US · Updated June 2026
Quick verdict
Both are xAI models. Grok Code Fast 1 is the newer, generally stronger default; reach for Grok 4 when a specific cost or latency profile matters more than the latest capabilities.
Grok 4 and Grok Code Fast 1 are both xAI models, so the real question is not which lab to trust but which tier fits your workload and budget. Grok 4 is xAI's 2M-context model with live data access and strong reasoning chops. Grok Code Fast 1 is xAI's speed-tier coding model at $0.20/$1.50 with a 256K window — cheap, fast agentic code over frontier quality. Since both come from the same lab, the comparison below focuses on the tier-and-cost trade-offs that actually separate them.
Key differences at a glance
▸Price: Grok Code Fast 1 is about 15× cheaper on input ($0.2/$1.5 per 1M tokens vs $3/$15 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 256K (~384 pages). Tie on paper — test on your own long inputs, since usable recall varies by model.
▸Recency: Grok Code Fast 1 is the newer model by about 50 days (released August 28, 2025), usually meaning fresher training data and capabilities.
Side-by-side specs
Spec
Grok 4
Grok Code Fast 1
Provider
xAI (US)
xAI (US)
Released
July 9, 2025
August 28, 2025
Context window
256K (~384 pages)
256K (~384 pages)
Price (in/out)
$3/$15 per 1M tokens
$0.2/$1.5 per 1M tokens
Open weight?
No — API only
No — API only
Modalities
text, image, code
text, code
SWE-Bench Verified
Not published
Not published
MRCR v2 @ 1M
Not published
Not published
Who wins what
256K context with native tool use
Grok 4
Grok 4 lists 256K context with native tool use among its strengths; Grok Code Fast 1 does not.
Real-time data via X integration
Grok 4
Grok 4 lists real-time data via X integration among its strengths; Grok Code Fast 1 does not.
Strong academic reasoning
Grok 4
Grok 4 lists strong academic reasoning among its strengths; Grok Code Fast 1 does not.
Fast, cheap agentic coding at $0.20/$1.50
Grok Code Fast 1
At $0.2/$1.5 per 1M tokens it undercuts Grok 4 ($3/$15 per 1M tokens), and that gap compounds at volume.
Low-latency code generation and terminal tasks
Grok Code Fast 1
XAI's speed-tier coding model at $0.20/$1.50 with a 256K window — cheap, fast agentic code over frontier quality — and it runs cheaper at $0.2/$1.5 per 1M tokens.
High-volume coding pipelines where speed beats peak quality
Grok Code Fast 1
XAI's speed-tier coding model at $0.20/$1.50 with a 256K window — cheap, fast agentic code over frontier quality — and it is the newer of the two.
Lowest cost at scale
Grok Code Fast 1
At $0.2/$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
→ Grok Code Fast 1
At $0.2/$1.5 per 1M tokens it undercuts Grok 4, and on millions of tokens that margin decides the monthly bill.
Anyone whose priority is 256k context with native tool use
→ Grok 4
It is specifically built for that.
Anyone whose priority is fast, cheap agentic coding at $0.20/$1.50
→ Grok Code Fast 1
That is its strongest area.
Grok 4: where it fits
XAI's 2M-context model with live data access and strong reasoning chops. Released July 9, 2025 by xAI, it is built for 256K context with native tool use, real-time data via X integration, strong academic reasoning, and no long-context surcharge.
Its trade-offs are real: smaller ecosystem than OpenAI/Google, and less independent benchmark coverage. At $3 in / $15 out per million tokens, it sits in the mid price band.
Grok Code Fast 1: where it fits
XAI's speed-tier coding model at $0.20/$1.50 with a 256K window — cheap, fast agentic code over frontier quality. Released August 28, 2025 by xAI, it is built for fast, cheap agentic coding at $0.20/$1.50, low-latency code generation and terminal tasks, high-volume coding pipelines where speed beats peak quality, and a 256K window sized for real codebases.
Its trade-offs: text and code only — no image, audio or video input, xAI did not publish a SWE-Bench Verified score, a speed-tier coding model, not a frontier reasoner, and narrow focus — built for code, not general knowledge work. At $0.2 in / $1.5 out per million tokens, it sits in the budget price band.
The bottom line for this matchup
Because Grok 4 and Grok Code Fast 1 come from the same lab (xAI), they share the same training philosophy and ecosystem — the decision is purely tier vs. cost. Grok Code Fast 1 is the more capable, more recent option; the other earns its place only when its price or latency profile fits a specific job better. Most teams should default to Grok Code Fast 1 and drop down only with a concrete reason.
Want both Grok 4 and Grok Code Fast 1 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.
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, Grok 4 leans toward 256k context with native tool use while Grok Code Fast 1 leans toward fast, cheap agentic coding at $0.20/$1.50, and that positioning usually predicts which feels better on your codebase.
Which is cheaper, Grok 4 or Grok Code Fast 1?
Grok Code Fast 1 is cheaper — $3/$15 per 1M tokens vs $0.2/$1.5 per 1M tokens, roughly 15× apart on input.
Which has the bigger context window?
Both advertise 256K (~384 pages). Remember advertised ≠ usable: recall typically degrades before the ceiling.
Should I upgrade from Grok 4 to Grok Code Fast 1?
Since both are xAI models, the newer one (Grok Code Fast 1) is usually the better default unless you need a specific cost or latency profile from the other.
Which is newer, Grok 4 or Grok Code Fast 1?
Grok Code Fast 1 — released August 28, 2025, about 50 days after Grok 4.
Specifications and benchmarks reflect publicly reported figures as of June 2026 and may change as providers release updates. Always verify on your own workload.