GPT-6.1 Sol vs Claude Sonnet 5.5 vs Grok 4.7: The $2-Tier Showdown (October 2026)

Three labs, three workhorses, one price band. GPT-6.1 Sol, Claude Sonnet 5.5 and Grok 4.7 are the models most production traffic should sit on in October 2026 — reasoning-capable, tool-fluent, built for all-day agent and coding work — and they cost between $1.60 and $2.00 per million input tokens. When pricing is this tight, the decision moves to context, vision, output price and the shape of your workload.

This is a spec-driven comparison using the live MeshTok catalog on 2026-10-19 (verifiable on the pricing page); no synthetic benchmarks, just the specs that move bills and the workload math that follows from them.

The contenders side by side

All three are callable through one OpenAI-compatible endpoint at https://meshtok.com/v1:

Field	openai/gpt-6.1-sol	anthropic/claude-sonnet-5.5	x-ai/grok-4.7
Input $/M	$2.00	$2.00	$1.60
Output $/M	$10.00	$10.00	$4.80
Context	1,000,000	1,000,000	500,000
Vision	—	yes	—
Flagship tag	—	—	yes
Released	2026-10	2026-10	2026-10

The spread looks boring until you read the columns carefully:

1. Grok wins both price columns — 20% cheaper input and less than half the output price. Code generation, long reports and agent transcripts are output-heavy; this column moves real money.
2. Sonnet wins the capability row — it is the only one with native vision, which matters for screenshot-driven debugging, UI verification, and document-image pipelines.
3. Context splits 1M vs 500K — Sol and Sonnet swallow twice the working set. Whole-monorepo prompts and hour-long agent transcripts live comfortably at 1M; Grok’s 500K still covers most codebases but is the first wall you will hit.
4. Grok carries the flagship tag while Sol and Sonnet sit a rung below their families’ flagships (Astra, Opus 5.5) — xAI positions 4.7 as its top model, period.

What a month of each costs

Reference workload: 1M input + 0.25M output tokens daily, 30 days:

Model	Daily	Monthly
Grok 4.7	$1.60 + $1.20 = $2.80	$84.00
GPT-6.1 Sol	$2.00 + $2.50 = $4.50	$135.00
Claude Sonnet 5.5	$2.00 + $2.50 = $4.50	$135.00

The output-heavy variant (1M in + 1M out daily — generation pipelines, heavy agent runs) is where the gap becomes structural: Grok 4.7 costs $192/month versus $360 for Sol or Sonnet. Nearly half the bill for the same token throughput is not a rounding error; it is a budget line.

Per-model breakdown

GPT-6.1 Sol — the ecosystem default ($2.00 / $10.00)

The refreshed OpenAI workhorse: 1M context, reasoning + tools, and the widest third-party integration surface of the three (every agent framework, IDE plugin and prompt library assumes OpenAI-shaped behavior first). The 6.1 refresh is a free upgrade over 6 Sol at identical pricing. Pick Sol when ecosystem compatibility outranks cost and you do not need vision.

Claude Sonnet 5.5 — the capability pick ($2.00 / $10.00)

Same pricing as Sol with two extra cards: a vision tag (the only one of the trio that reads screenshots and document images natively) and Claude’s house style for long instruction adherence in multi-tool agent chains. Its 1M window matches Sol. Pick Sonnet 5.5 when your traffic includes images or when agent reliability over long tool chains is the binding constraint.

Grok 4.7 — the value pick ($1.60 / $4.80)

xAI’s actual flagship at workhorse pricing: 43% cheaper per mixed-token month than either rival, with the flagship tag the other two do not carry. The compromises — 500K context, no vision — are real but narrow. Pick Grok 4.7 when the workload is text-and-tools, output volume is high, and the monthly bill is the metric your team is judged on.

Tie-breakers by workload

Your workload	Pick	Why
High-volume code generation	Grok 4.7	$4.80/M output halves the dominant cost
Screenshot debugging, UI checks	Sonnet 5.5	only vision tag in the trio
Hour-long agent transcripts, monorepo prompts	Sol or Sonnet 5.5	1M context headroom
Mixed production traffic, cost-capped	Grok 4.7	flagship quality at 62% of the tier price
Framework-first team (agent SDKs, plugins)	GPT-6.1 Sol	widest ecosystem assumptions
Long-document RAG above 500K	Sol or Sonnet 5.5; Grok 4.1-fast ($0.20/$0.50, 2M) for pure volume	context + budget

When none of the three is right

• Cheaper still, same mission: deepseek/deepseek-v4-pro at $0.67/$1.34 carries flagship, reasoning, vision and a 1M window — $30/month on the reference workload. It trades Western-lab ecosystem conventions for the price.
• Stronger, pricier: anthropic/claude-opus-5.5 ($4.00/$20.00) or openai/gpt-6-astra ($10.00/$50.00) for the hardest agentic work — the tier above costs 2.2× to 8× more.
• Pure speed tier: openai/gpt-6-luna ($0.10/$0.50) and x-ai/grok-4.1-fast ($0.20/$0.50, 2M context) undercut all three by an order of magnitude when reasoning depth is not the constraint.

Run the A/B yourself

All three are one model string apart on the same endpoint:

from openai import OpenAI

client = OpenAI(
    base_url="https://meshtok.com/v1",
    api_key="sk-your-MeshTok-key",
)

for model in ["openai/gpt-6.1-sol", "anthropic/claude-sonnet-5.5", "x-ai/grok-4.7"]:
    resp = client.chat.completions.create(
        model=model,
        messages=[{"role": "user", "content": "Your production prompt here"}],
    )
    print(model, resp.usage.total_tokens)

Route a day of real traffic through each, weigh quality against the $84-vs-$135 gap, and let your own prompts pick the winner. Prices reflect the catalog on 2026-10-19 — live figures on the pricing page, per-model detail on the model pages.