Model comparison

GPT-5.6 Terra vs Grok 4.6

OpenAI's GPT-5.6 Terra against xAI's Grok 4.6: vendor list prices, limits, abilities and the Artificial Analysis indexes side by side - and what OpenSmartRoute does when both are available.

CheaperGrok 4.6

Grok 4.6 lists at $3.00 per million tokens blended against $4.50 for GPT-5.6 Terra - 1.5x less.

Stronger on intelligenceGrok 4.6

Grok 4.6 scores 44 on the intelligence index against 42 - 2 points apart.

Coding: levelEven

Coding index 77 against 77: within a point of each other.

Stronger on agenticGrok 4.6

Grok 4.6 scores 53 on the agentic index against 43 - 10 points apart.

Longer contextGPT-5.6 Terra

GPT-5.6 Terra reads 1.1M tokens at once, Grok 4.6 500k.

NewerGrok 4.6

Grok 4.6 was released about 1 month later.

Side by side

Vendor list prices per million tokens and published limits; indexes are Artificial Analysis composites (0-100).

Specification	GPT-5.6 Terra	Grok 4.6
Input price / 1M tokens	$2.00	$2.00
Output price / 1M tokens	$12.0	$6.00
Blended (3 in : 1 out)	$4.50	$3.00
Cached input / 1M	$0.20	$0.50
Context window	1.1M	500K
Max output	128K	450K
Input	file, image, text	text, image, file
Output	text	text
Tool calls
Structured output
Reasoning
Open weights
Intelligence index	42	44
Coding index	77	77
Agentic index	43	53
Released	Jul 9, 2026	Aug 12, 2026
Available on this deployment

What a month costs

List price times tokens for three typical workloads; your mix of input and output decides which model's pricing suits you.

Workload	GPT-5.6 Terra	Grok 4.6	Difference
Support chat20M tokens in, 5M out a month - a help desk answering a few thousand conversations.	$100	$70.00	$30.00 less on Grok 4.6
Document summaries100M in, 5M out - long inputs, short answers.	$260	$230	$30.00 less on Grok 4.6
Coding assistant60M in, 20M out - a team's editor assistant, output-heavy.	$360	$240	$120 less on Grok 4.6

What the router does with the pair

Grok 4.6 is both cheaper and stronger on the intelligence index, so with both in the catalogue the router sends it almost everything; GPT-5.6 Terra earns a request only on something it alone offers - a longer context, a modality, a data boundary or a region your rules require.

Price a request Playground

yaml

# targets.yaml - both models as routing targets (metadata.model links each to the catalogue entry)
targets:
  - { id: grok-4.6, kind: llm, metadata: { model: x-ai/grok-4.6 } }
  - { id: gpt-5.6-terra, kind: llm, metadata: { model: openai/gpt-5.6-terra } }

# rules.yaml - the cheaper model by default, the stronger one when the request is hard
rules:
  - name: simple-requests-stay-cheap
    when: { max_complexity: 0.45 }
    prefer: [grok-4.6]
    weight: 0.8
  - name: hard-requests-escalate
    when: { min_complexity: 0.45 }
    prefer: [gpt-5.6-terra]
    weight: 0.8

Frequently asked

Is GPT-5.6 Terra cheaper than Grok 4.6?: No. GPT-5.6 Terra lists at $2.00 in / $12.0 out per million tokens, Grok 4.6 at $2.00 in / $6.00 out; blended, Grok 4.6 is the cheaper one.
Which is better, GPT-5.6 Terra or Grok 4.6?: On the Artificial Analysis intelligence index Grok 4.6 scores higher (44 against 42). "Better" depends on the task: the coding and agentic indexes below and the abilities row may point the other way for your requests.
Which has the longer context window?: GPT-5.6 Terra - 1.1M tokens against 500K.
Can I use GPT-5.6 Terra and Grok 4.6 together?: Yes. Declare both as targets and OpenSmartRoute picks one per request on quality for the task, price and your rules - the cheaper model for the requests it can answer, the stronger one for the rest - and records why in the trace.

Also compared

Every OpenAI and xAI model, with prices, is on the vendor pages; the rankings show what the router actually picks.

For the business

What it means for which models you pay for.

Catalogue of every vendor
The right model, not the famous one
Price, context, abilities and benchmark indexes side by side, with the model that fits each task named.
The rankings
89% less
Lower cost per request
On the 150-prompt benchmark the router spent 89% less than sending every prompt to the reference model, and the judged quality went up, not down.
Read the benchmark
Per million tokens, every model
Prices you can compare
The catalogue prints input and output prices and what three typical monthly workloads cost on each.
The model catalogue

Which LLM is the cheapest for our workload?: The best-for pages rank the live catalogue per task by the index that measures it, and the router picks the cheapest model that meets your quality rule for each request.
How much can we save on our LLM bill?: On the public benchmark the router saved 89% against sending everything to the reference model. Import last month's provider bill on the bill page and the estimate is computed on your own traffic before you change a line of code.
How often do model prices change?: The catalogue is refreshed from the vendors' price lists; each model page shows the date of its data.

Stop choosing between GPT-5.6 Terra and Grok 4.6. Route to both.

Declare the pair as targets and OpenSmartRoute picks per request - the cheaper one where it holds up, the stronger one where it matters - with the comparison in every trace.

Create a free account Try a request

Free plan, no card. Fifteen thousand decisions a month with the full trace.

Specification

GPT-5.6 Terra

Grok 4.6

Input price / 1M tokens

$2.00

Output price / 1M tokens

$12.0

$6.00

Blended (3 in : 1 out)

$4.50

$3.00

Cached input / 1M

$0.20

$0.50

Context window

1.1M

500K

Max output

128K

450K

Input

file, image, text

text, image, file

Output

text

Tool calls

Structured output

Reasoning

Open weights

Intelligence index

Coding index

Agentic index

Released

Jul 9, 2026

Aug 12, 2026

Available on this deployment

Workload

GPT-5.6 Terra

Grok 4.6

Difference

Support chat20M tokens in, 5M out a month - a help desk answering a few thousand conversations.

$100

$70.00

$30.00 less on Grok 4.6

Document summaries100M in, 5M out - long inputs, short answers.

$260

$230

$30.00 less on Grok 4.6

Coding assistant60M in, 20M out - a team's editor assistant, output-heavy.

$360

$240

$120 less on Grok 4.6

What the router does with the pair

# targets.yaml - both models as routing targets (metadata.model links each to the catalogue entry) targets: - { id: grok-4.6, kind: llm, metadata: { model: x-ai/grok-4.6 } } - { id: gpt-5.6-terra, kind: llm, metadata: { model: openai/gpt-5.6-terra } } # rules.yaml - the cheaper model by default, the stronger one when the request is hard rules: - name: simple-requests-stay-cheap when: { max_complexity: 0.45 } prefer: [grok-4.6] weight: 0.8 - name: hard-requests-escalate when: { min_complexity: 0.45 } prefer: [gpt-5.6-terra] weight: 0.8

Frequently asked

Is GPT-5.6 Terra cheaper than Grok 4.6?

No. GPT-5.6 Terra lists at $2.00 in / $12.0 out per million tokens, Grok 4.6 at $2.00 in / $6.00 out; blended, Grok 4.6 is the cheaper one.

Which is better, GPT-5.6 Terra or Grok 4.6?

On the Artificial Analysis intelligence index Grok 4.6 scores higher (44 against 42). "Better" depends on the task: the coding and agentic indexes below and the abilities row may point the other way for your requests.

Which has the longer context window?

GPT-5.6 Terra - 1.1M tokens against 500K.

Can I use GPT-5.6 Terra and Grok 4.6 together?

Yes. Declare both as targets and OpenSmartRoute picks one per request on quality for the task, price and your rules - the cheaper model for the requests it can answer, the stronger one for the rest - and records why in the trace.

GPT-5.6 Terra vs Grok 4.6

Side by side

What a month costs

What the router does with the pair

Frequently asked

Also compared

What it means for which models you pay for.

The right model, not the famous one

Lower cost per request

Prices you can compare

Stop choosing between GPT-5.6 Terra and Grok 4.6. Route to both.

GPT-5.6 Terra vs Grok 4.6

Side by side

What a month costs

What the router does with the pair

Frequently asked

Also compared

What it means for which models you pay for.

The right model, not the famous one

Lower cost per request

Prices you can compare

Stop choosing between GPT-5.6 Terra and Grok 4.6. Route to both.