Grok 4.20
Where it stands
Quality in independent tests against price, next to 135 other models. Up means more capable, left means cheaper.
About this model
Grok 4.20 is an AI model from xAI, made available through the API on March 31, 2026. It can read up to 2,000,000 tokens in one request, roughly 3,750 pages of text, and write up to 1,800,000 tokens in a single answer. Besides text, it accepts images and files such as PDFs as input.
Through the API it costs $1.25 per million input tokens and $2.50 per million output tokens. Its pricing sits in the middle of the market.
It supports extended reasoning: it can "think" step by step before answering, which helps on maths, code and complex questions. It can call tools and functions, so developers can connect it to search, databases or other software.
Quality scores
Rankings →Where to use it
Companies that serve this model through an API: 4. Prices per million tokens, cheapest first.
| Provider | Inputi | Outputi | Contexti | Uptime (24 h)i |
|---|---|---|---|---|
xAIOfficialCheapest | $1.25 | $2.50 | 2M | 99.6% |
xAIOfficialCheapest | $1.25 | $2.50 | 2M | 99.8% |
xAIOfficial | $2.50 | $5 | 2M | 100.0% |
xAIOfficial | $2.50 | $5 | 2M | 100.0% |
Availability and prices come from OpenRouter’s public API and are refreshed daily. Uptime is the share of successful requests over the last 24 hours. Some providers run a compressed version of open models (fp8, int4), which is cheaper but can be slightly less accurate.
Use it in your code
Call Grok 4.20 through OpenRouter’s OpenAI-compatible API: create a key on openrouter.ai, then run one of these examples.
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": "Hello! What can you do?"}]}'import os
from openai import OpenAI
client = OpenAI(base_url="https://openrouter.ai/api/v1", api_key=os.environ["OPENROUTER_API_KEY"])
reply = client.chat.completions.create(
model="x-ai/grok-4.20",
messages=[{"role": "user", "content": "Hello! What can you do?"}],
)
print(reply.choices[0].message.content)import OpenAI from "openai";
const client = new OpenAI({ baseURL: "https://openrouter.ai/api/v1", apiKey: process.env.OPENROUTER_API_KEY });
const reply = await client.chat.completions.create({
model: "x-ai/grok-4.20",
messages: [{ role: "user", content: "Hello! What can you do?" }],
});
console.log(reply.choices[0].message.content);The same code works with every model on this site: only the model ID changes. Many labs also offer their own API and SDK.
What it costs in practice
- 1,000 chat replies$1.38
- Summarise a 100-page document$0.065
- An app with 10,000 requests a day for a month$675
Similar-priced alternatives
| Model | Inputi | Outputi | Contexti | |
|---|---|---|---|---|
Muse Spark 1.3Meta | $1.25 | $4.25 | 1M | Compare with ⇄ |
GLM 5V TurboZ.ai (Zhipu) | $1.20 | $4 | 198K | Compare with ⇄ |
Qwen3.7 MaxAlibaba Qwen | $1.48 | $4.43 | 1M | Compare with ⇄ |
Gemini 3.5 FlashGoogle DeepMind | $1.50 | $9 | 1M | Compare with ⇄ |
Mistral Medium 3.5Mistral AI | $1.50 | $7.50 | 256K | Compare with ⇄ |
InklingThinking Machines Lab | $1 | $4.05 | 512K | Compare with ⇄ |
News about xAI
See all →Frequently asked questions
- How much does Grok 4.20 cost?
- Grok 4.20 costs $1.25 per million input tokens and $2.50 per million output tokens through the API. For example, 1,000 chat replies of about 500 tokens in and 300 out cost around $1.38.
- What is the context window of Grok 4.20?
- Grok 4.20 can read up to 2,000,000 tokens in one request, about 3,750 pages of text. It can write up to 1,800,000 tokens in a single answer.
- Is Grok 4.20 open source?
- No. Grok 4.20 is a closed model: its weights are not published, so you use it through xAI’s own apps and API, or through cloud providers.
- Who makes Grok 4.20?
- Grok 4.20 is made by xAI. It became available through the API on March 31, 2026.
- How good is Grok 4.20?
- Grok 4.20 has an overall index of 152.0 in Epoch AI’s independent tests, ranking #37 of 136 models we track.
- Can Grok 4.20 read images?
- Yes. Besides text, it accepts images and files such as PDFs as input.
- What are the alternatives to Grok 4.20?
- Models with a similar price from other companies include Muse Spark 1.3, GLM 5V Turbo and Qwen3.7 Max. You can compare them side by side on this page.