HEAD-TO-HEAD · BUDGET-TIER · VERIFIED OCTOBER 31, 2026

GPT-6.1 Terra or GPT-4o mini — which one is actually cheaper to run?

GPT-6.1 Terra ($1/$5 per M tokens) and GPT-4o mini ($0.15/$0.6 per M tokens) sit at opposite ends of OpenAI's pricing ladder. Terra costs roughly 7-8x more per token in both directions, so the choice comes down to how much that pricing gap matters for your workload.

Spec	GPT-6.1 Terra	GPT-4o mini
Input / 1M tokens	$1.00	$0.15
Output / 1M tokens	$5.00	$0.60
Context window	128K (unconfirmed)	128K

The output price gap

The output-token gap is the bigger story here: GPT-6.1 Terra charges $5 per million output tokens versus just $0.6 for GPT-4o mini — a difference of $4.40 per million tokens. For output-heavy workloads like long-form generation, summarization, or chatty agents, this gap compounds fast and will dominate your bill far more than the input price difference.

Context window

GPT-4o mini has a confirmed 128K-token context window. GPT-6.1 Terra's context window isn't independently verified in this check — based on naming conventions and typical OpenAI tiering, 128K is a reasonable estimate, but treat this figure as uncertain until confirmed against OpenAI's official docs.

Worked example

At 100M input + 30M output tokens per month: GPT-6.1 Terra costs (100 x $1) + (30 x $5) = $100 + $150 = $250/month. GPT-4o mini costs (100 x $0.15) + (30 x $0.6) = $15 + $18 = $33/month. That's a difference of $217/month, with GPT-4o mini costing roughly 7.6x less for this workload.

Prices from the LLM Price Watch daily tracker, 2026-10-31. Prices change; use the calculator with your own usage for an exact comparison, or see the full price table for every tracked model.

Frequently asked questions

Is GPT-4o mini still available to use?

As of this check, GPT-4o mini remains active via the OpenAI API with its standard $0.15/$0.6 per million token pricing. Some trackers note a future deprecation timeline, so if long-term stability matters for your project, confirm current status directly on OpenAI's pricing page before committing.

Why is GPT-6.1 Terra so much more expensive than GPT-4o mini?

GPT-6.1 Terra is positioned as a more capable, higher-tier model, which typically means stronger reasoning, better instruction-following, or newer training data compared to the smaller, budget-focused GPT-4o mini. Higher capability models generally carry proportionally higher per-token costs across the industry.

Which model is cheaper for output-heavy tasks?

GPT-4o mini is dramatically cheaper for output-heavy tasks, charging $0.6 per million output tokens versus $5 for GPT-6.1 Terra. For workloads dominated by generation rather than reading input, this gap makes GPT-4o mini the clear economical choice unless Terra's extra capability is essential.

Should I always choose the cheaper model?

Not necessarily — price is only one factor. If GPT-6.1 Terra delivers meaningfully better accuracy, reasoning, or reliability for your specific task, the extra cost may be worth it, especially at lower volumes where the absolute dollar difference is small.