API cost decision in 10 seconds

GPT-5.5 Pro vs Grok 4.20 Multi-Agent

Pick Grok 4.20 Multi-Agent when budget and context both matter.

Pricing data updated:  Prices normalized to USD per 1M tokens Sample workload: 1M input + 500K output

Budget verdict

Pick Grok 4.20 Multi-Agent when budget and context both matter.

On the standard 1M input plus 500K output workload, Grok 4.20 Multi-Agent is estimated at $5 vs $120 for GPT-5.5 Pro, saving $115 (95.8% lower).

Cost-first pickGrok 4.20 Multi-Agent
Context-first pickGrok 4.20 Multi-Agent
Sample savings$11595.8%
10x traffic gap$1150

Grok 4.20 Multi-Agent is cheaper on the standard workload and also has the larger context window. At 10x that traffic, the same price gap is about $1150. Use the calculator below to replace the sample workload with your own token volume.

Cost sensitivity

Workload Sensitivity

Same prices, different token mixes.

Grok 4.20 Multi-Agent stays cheaper across input-heavy, balanced, and output-heavy sample workloads.

Workload shapeToken mixBetter pickGPT-5.5 ProGrok 4.20 Multi-Agent
Input-heavy / RAG5M input + 500K outputGrok 4.20 Multi-Agent$240$13
Balanced workload1M input + 1M outputGrok 4.20 Multi-Agent$210$8
Output-heavy chatbot1M input + 5M outputGrok 4.20 Multi-Agent$930$32
Cheaper input Grok 4.20 Multi-Agent $30 vs $2 / 1M

Grok 4.20 Multi-Agent is $28 cheaper per 1M input tokens (93.3% lower; 15x difference).

Cheaper output Grok 4.20 Multi-Agent $180 vs $6 / 1M

Grok 4.20 Multi-Agent is $174 cheaper per 1M output tokens (96.7% lower; 30x difference).

Larger context Grok 4.20 Multi-Agent 1.05M vs 2M

Grok 4.20 Multi-Agent has 950K more context (1.9x larger).

Sample workload Grok 4.20 Multi-Agent $120 vs $5

Grok 4.20 Multi-Agent is $115 cheaper on the standard workload (95.8% lower).

Estimate your workload cost

Your Workload Cost

Prices are normalized to USD per 1M tokens.
GPT-5.5 Pro Calculating… Estimated API cost
Grok 4.20 Multi-Agent Calculating… Estimated API cost
Cheaper for this workload Calculating… Difference: calculating…

This estimate uses normalized public API pricing per 1M tokens. It is a planning aid, not a billing quote. Verify provider pricing, limits, and terms before production use.

Quick Decision

Verdict

Grok 4.20 Multi-Agent has the lower input price; Grok 4.20 Multi-Agent has the lower output price; Grok 4.20 Multi-Agent offers the larger context window. For the 1M input plus 500K output sample, Grok 4.20 Multi-Agent is cheaper for the standard workload.

For a 1M input token plus 500K output token workload, the estimated API cost is $120 for GPT-5.5 Pro and $5 for Grok 4.20 Multi-Agent.

Best Fit

Choose GPT-5.5 Pro when its provider, model quality, latency, or availability is more important than the numeric price/context winner.

Choose Grok 4.20 Multi-Agent when you care most about lower input-token price, lower output-token price, and larger context window.

Decision Notes
  • On the standard 1M input plus 500K output workload, Grok 4.20 Multi-Agent is estimated at $5 vs $120 for GPT-5.5 Pro, saving $115 (95.8% lower).
  • Grok 4.20 Multi-Agent is $115 cheaper on the standard workload (95.8% lower).
  • Grok 4.20 Multi-Agent is $28 cheaper per 1M input tokens (93.3% lower; 15x difference).
  • Grok 4.20 Multi-Agent is $174 cheaper per 1M output tokens (96.7% lower; 30x difference).
  • Grok 4.20 Multi-Agent has 950K more context (1.9x larger).
Head-to-Head Specs
FeatureGPT-5.5 Pro
(OpenAI)		Grok 4.20 Multi-Agent
(xAI)
Input Price
prompt tokens per 1M		$30$2
Completion Price
per 1M tokens		$180$6
Sample Workload Cost
1M input + 500K output		$120$5
Context Window1.05M2M
Release Date

Use-Case Decision Matrix

Use caseBetter pickWhy
Budget-constrained productionGrok 4.20 Multi-AgentOn the standard 1M input plus 500K output workload, Grok 4.20 Multi-Agent is estimated at $5 vs $120 for GPT-5.5 Pro, saving $115 (95.8% lower).
High-volume input processingGrok 4.20 Multi-AgentLower prompt-token price matters most when prompts, retrieved passages, or documents dominate the bill.
Long responses and chatbotsGrok 4.20 Multi-AgentLower output-token price matters most when assistants generate many completion tokens.
RAG or long-document workGrok 4.20 Multi-AgentA larger context window leaves more room for retrieved passages, conversation history, or source files.

Related Alternatives

Same-provider lower-cost swaps
  • gpt-oss-120b (free) can replace GPT-5.5 Pro when lower sample workload cost matters most: $0.
  • gpt-oss-20b (free) can replace GPT-5.5 Pro when lower sample workload cost matters most: $0.
  • gpt-oss-20b can replace GPT-5.5 Pro when lower sample workload cost matters most: $0.1.
  • gpt-oss-120b can replace GPT-5.5 Pro when lower sample workload cost matters most: $0.13.
Larger context near this budget
  • Llama 4 Scout offers 10M context with $0.23 sample workload cost.
Popular competitors
  • No popular competitor is currently available.

Cheaper alternatives

Review low-cost models sorted by a standard 1M input plus 500K output workload.

Open cheapest models

Larger context alternatives

Find models with larger context windows for RAG, long documents, and codebase review.

Open largest context models

Provider catalogs

Compare models within provider hubs before choosing a final API vendor.

Open provider hubs

OpenAI catalog

Review all tracked OpenAI models before deciding whether this matchup is the right shortlist.

Open OpenAI models

xAI catalog

Check other xAI models with comparable pricing, context, or release timing.

Open xAI models
GPT-5.5 Pro

GPT-5.5 Pro is OpenAI’s high-capability model optimized for deep reasoning and accuracy on complex, high-stakes workloads. It features a 1M+ token context window (922K input, 128K output) with support for...

Grok 4.20 Multi-Agent

Grok 4.20 Multi-Agent is a variant of xAI’s Grok 4.20 designed for collaborative, agent-based workflows. Multiple agents operate in parallel to conduct deep research, coordinate tool use, and synthesize information...