X-aiReasoningReleased 31 March 2026
Grok 4.20 pricing, context and benchmark
Grok 4.20 is a reasoning model from SpaceXAI with industry-leading speed and agentic tool calling capabilities.
2M
Input context
1.80M
Output context
$1.25
Official input
$2.5
Official output
n/a
AA index
01 · Model Overview
Everything that matters, in one table
Context, pricing, cache, modalities and tooling, from the model registry and Artificial Analysis.
| Model | Grok 4.20 |
| Model ID | x-ai/grok-4.20 |
| Provider | X-ai |
| Release date | 31 March 2026 |
| Status | Generally available |
| Input context | 2,000,000 tokens |
| Output context | 1,800,000 tokens |
| Official input pricing | $1.25 per 1M tokens |
| Official output pricing | $2.5 per 1M tokens |
| Cache read pricing | $0.2 per 1M tokens (84% off input) |
| Market input pricing | $1.25 per 1M (cheapest route) |
| Market output pricing | $2.5 per 1M (cheapest route) |
| Highest route pricing | $2.5 in, $5 out per 1M |
| Input modalities | text · image · file |
| Output modalities | text |
| Reasoning control | Not exposed |
| Tool support | Text generation only |
| Tokenizer | Grok |
| Provider routes | 4 endpoints |
| Artificial Analysis index | Not published |
| Speed | 80 tokens/s, 20.21s to first token |
| Knowledge cutoff | Not publicly stated |
Input and output support
| Modality | Input | Output | Billed at |
|---|---|---|---|
| Text | ✓ yes | ✓ yes | $1.25 in |
| Image | ✓ yes | no | $1.25 in |
| Audio | no | no | not supported |
| Video | no | no | not supported |
| File (PDF) | ✓ yes | no | $1.25 in |
02 · Overview
What is Grok 4.20?
Grok 4.20 is a reasoning model from SpaceXAI with industry-leading speed and agentic tool calling capabilities.
It combines the lowest hallucination rate on the market with strict prompt adherance, delivering...
Grok 4.20 carries a 2M token window, uses the Grok tokenizer and is served by X-ai. On Hoodgen it sits in the Reasoning tier of the model menu next to its siblings, so you can switch mid conversation without losing the thread.
03 · Release
Release and what changed from the previous version
Released31 March 2026
This is the only release of Grok 4.20 on OpenRouter, released 31 March 2026. The provider has not published a knowledge cutoff, so treat training data as recent but unconfirmed for very new events.
04 · Capabilities
Features and capabilities
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Vision
Screenshots, charts and photographed documents are read at the text token rate.
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Files and PDFs
Documents go in as files rather than pasted text, keeping layout and tables intact.
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Prompt caching
Cached input costs $0.2 per million instead of $1.25, so stable prefixes get cheaper.
07 · Use cases
What can you do with Grok 4.20?
Debugging and root cause
Multi file failures where the model has to hold a causal chain before answering.
Architecture and planning
Design docs, migration plans and trade off analysis over long context.
Data analysis
Spreadsheets and logs read in one pass, then summarised with the numbers quoted back.
Agentic coding
Repo wide changes that need plan, edit and verify loops.
08 · Cost levers
Prompt caching and how to cut the bill
Cached input bills at $0.2 per million instead of $1.25, a 84% discount. Keep the system prompt and documents first and the changing question last, so every call hits the cache.
09 · Pricing
Grok 4.20 pricing
Official pricing
List price
$1.25 / 1M in
$2.5 / 1M out
- $0.2 cached input
- 2M context
- text, image, file input
Cheapest route
$1.25 / 1M in
$2.5 / 1M out
- 4 routes on OpenRouter
- What Hoodgen routes to first
- Same model, lower bill
Highest route
$2.5 / 1M in
$5 / 1M out
- Priority or premium tier
- Best under load
- Use for latency critical calls
Market pricing, every route
| Provider | Tier | Input | Output | Cache read | Uptime 24h |
|---|---|---|---|---|---|
| xAI | standard | $1.25 | $2.5 | $0.2 | 99.6% |
| xAI | standard | $1.25 | $2.5 | $0.2 | 100.0% |
| xAI | priority | $2.5 | $5 | $0.4 | 100.0% |
| xAI | priority | $2.5 | $5 | $0.4 | n/a |
API pricing and cost calculator
| Rate | Per call | Total | Credits |
|---|---|---|---|
| Cheapest route | $0.0161 | $8.07 | 7672 |
| List price | $0.0162 | $8.08 | 7672 |
| Highest route | $0.0575 | $28.75 | 27313 |
10 · Developers
API and developer information
| Model ID | x-ai/grok-4.20 |
| Endpoint | https://openrouter.ai/api/v1/chat/completions |
| Parameters | prompt and max_tokens |
| Streaming | Yes, server sent events |
| Modality string | text+image+file->text |
| Max prompt tokens | 2,000,000 |
| Max completion tokens | 1,800,000 |
curl https://openrouter.ai/api/v1/chat/completions \
-H "Authorization: Bearer $OPENROUTER_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"model": "x-ai/grok-4.20",
"messages": [{ "role": "user", "content": "Summarise this document." }],
"max_tokens": 1024
}'11 · Limitations
Model limitations
| Text only output | It cannot generate images, audio or video. Pair it with an image model on Hoodgen when you need visuals. |
| Output cap | 1,800,000 tokens per request. Long deliverables have to be chunked. |
| Benchmarks not published | Artificial Analysis does not publish an Intelligence Index for this release, so no benchmark score is claimed here. |
| Knowledge cutoff | The provider does not state a fixed cutoff for every release. Verify very recent events against search. |
12 · Comparison
Grok 4.20 vs other X-ai models
| Model | Context | Input /1M | Output /1M | AA index | Released |
|---|---|---|---|---|---|
| Grok 4.20 | 2M | $1.25 | $2.5 | n/a | 2026 |
| Grok 4.5 | 500K | $2 | $6 | n/a | 2026 |
| Grok 4.6 | 500K | $2 | $6 | n/a | 2026 |
| Grok Build 0.1 | 256K | $1 | $2 | n/a | 2026 |
13 · Privacy
Privacy and data policy
- On Hoodgen, prompts and attachments answer that request and stay in your conversation history so you can reopen it. They are not used to train models.
- Requests route through OpenRouter to X-ai and are covered by that provider's API terms.
- Do not paste secrets or personal data you would not send to any hosted model.
14 · FAQ
Grok 4.20 questions, answered
Grok 4.20 is a reasoning model from X-ai, released 31 March 2026. Grok 4.20 is a reasoning model from SpaceXAI with industry-leading speed and agentic tool calling capabilities.
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Start chatting with Grok 4.20
Free to try on Hoodgen AI, with a live credit estimate before every send. No API key, no setup.