Grok 4.20
legacyxAI · Frontier
Predecessor to Grok 4.3 with 2M context. Later aligned to Grok 4.3 pricing.
- Strengths
- Huge 2M-token context, later aligned to Grok 4.3 pricing.
- Best for
- Very long-context tasks that exceed a 1M window.
- Limitations
- Superseded by Grok 4.3.
Input / 1M
$1.25
Output / 1M
$2.50
Cached input / 1M
$0.2
Context window
2M
Where it sits
8th-cheapest frontier model
by blended $/Mtok among 24 listed frontier models
57% below the frontier median
blended $/Mtok across 24 frontier models
Output costs 2× input
$1.25 in / $2.50 out per 1M
Cached input saves 84%
$0.2 vs $1.25 per 1M fresh
Down 48% since launch (Mar 2026)
blended price vs launch
Computed live from current prices and this model's history — not hand-written, so it stays accurate as prices move.
Price history
Input (solid)Output (dashed)
Blended price change (3:1 I/O mix)
- 30d
- —
- 90d
- decreased 47.9%
- 1y
- decreased 47.9%
- Since launch
- decreased 47.9%
Snapshots
| Effective | Input | Output | Cached in | Note | Source |
|---|---|---|---|---|---|
| 12 May 2026 | $1.25 | $2.50 | $0.2 | Realigned to Grok 4.3 pricing; present by Wayback docs.x.ai capture 2026-05-12 (realignment bracketed 2026-04-01 → 2026-05-12) | docs.x.ai |
| 10 Mar 2026 | $2.00 | $6.00 | $0.2 | Launch pricing (OpenRouter; still $2/$6 at Wayback capture 2026-04-01) | openrouter.ai/x-ai/grok-4.20 |