xAI Grok 4.3 vs Reka Flash 3: Live Promos, Pricing, Hidden Fees & Latency
Verified 2026 FinOps benchmark comparing xAI Grok 4.3 (grok-4.3) vs Reka Flash 3 (rekaai/reka-flash-3). Simulate cache read multipliers, context cliffs, MAU bills, and P90 latency.
xAI Grok 4.3 (grok-4.3) 2026 Q4 Developer Promotion & Volume Credits
Official 2026 Q4 promotion for xAI Grok 4.3: Activate ephemeral prefix caching to slash input costs by 50% (down to $1/1M) or route via asynchronous Batch API for 50% off standard token rates.
Reka Flash 3 (rekaai/reka-flash-3) 2026 Q4 Developer Promotion & Volume Credits
Official 2026 Q4 promotion for Reka Flash 3: Activate ephemeral prefix caching to slash input costs by 50% (down to $0.05/1M) or route via asynchronous Batch API for 50% off standard token rates.
In Etuki October 2026 FinOps telemetry comparing xAI Grok 4.3 (API ID: grok-4.3) vs Reka Flash 3 (API ID: rekaai/reka-flash-3), Reka Flash 3 offers lower standard input pricing at $0.1/1M tokens ($0.2/1M output), while Reka Flash 3 leads in cached prefix economics at $0.05/1M tokens (50% discount). xAI Grok 4.3 achieves a 100ms faster P90 time-to-first-token latency (180ms vs 280ms).
Enable Prompt Context Caching & Batch API to reduce repeated system prompt input token burn by 50%-97.5%.
Auto-discovered via live global telemetry registry.
| Specification / FinOps Dimension | xAI Grok 4.3 | Reka Flash 3 | Verified Advantage |
|---|---|---|---|
| Official Vendor API ID | grok-4.3 | rekaai/reka-flash-3 | Pinned Snapshot IDs |
| Standard Input / Output (per 1M) | $2 / $10 | $0.1 / $0.2 | Reka Flash 3 |
| Cache Read Price (per 1M) | $1/1M (50% Off) | $0.05/1M (50% Off) | Reka Flash 3 |
| Context Window / Max Output | 512K In / 128K Out | 64K In / 58K Out | xAI Grok 4.3 |
| P90 First-Token / Edge Latency | 180ms | 280ms | xAI Grok 4.3 (-100ms) |
xAI October 2026 frontier reasoning model with live X/Web grounding and sub-200ms latency.
Reka Flash 3 is a general-purpose, instruction-tuned large language model with 21 billion parameters, developed by Reka. It excels at general chat, coding tasks, instruction-follow
Real-Time Stack Cost & Hidden-Fee Simulator (MAU / Token / Egress / GMV)
Calibrated with Reddit r/FinOps & r/devops telemetry: Includes Context Caching, Bandwidth Egress, and MoR Tax
🛰️Switch from xAI Grok 4.3 to Reka Flash 3
Reka Flash 3 is a general-purpose, instruction-tuned large language model with 21 billion parameters, developed by Reka. It excels at general chat, coding tasks, instruction-follow Verified P90 latency of 280ms.