GPT-5.6 Luna vs Inkling

OpenAI · US  |  Thinking Machines Lab · US · Updated June 2026

Quick verdict

Pick GPT-5.6 Luna for cheapest gpt-5.6 tier for high-volume drafting and automation or fast, affordable execution while keeping respectable coding. Pick Inkling for the first model release from mira murati's thinking machines lab (ex-openai cto) - one of the most closely-watched new labs in ai or a 975b-parameter moe (41b active) with native text, image, and audio reasoning in one model. Choose Inkling if you need self-hosting or data privacy; GPT-5.6 Luna if you want a managed API.

GPT-5.6 Luna (OpenAI) and Inkling (Thinking Machines Lab) are two of the models people most often weigh against each other in 2026. GPT-5.6 Luna is the budget, high-throughput GPT-5.6 tier — built for cheap, fast, large-volume work rather than deep long-context reasoning. Inkling is mira Murati's Thinking Machines Lab debuts with Inkling - a 975B open-weight MoE with native multimodal reasoning and a dialable thinking-effort control. They diverge most on price and open vs. closed weights — each quantified below from the models' real specs.

Key differences at a glance

Side-by-side specs

SpecGPT-5.6 LunaInkling
ProviderOpenAI (US) Thinking Machines Lab (US)
ReleasedJuly 9, 2026 July 15, 2026
Context window1M (~1,500 pages) 1M (~1,500 pages)
Price (in/out)$1/$6 per 1M tokens Open weight (self-host / free)
Open weight?No — API only Yes — self-hostable
Modalitiestext, image, code text, image, audio, code
SWE-Bench VerifiedNot published Not published
MRCR v2 @ 1MNot published Not published

Who wins what

Cheapest GPT-5.6 tier for high-volume drafting and automation

GPT-5.6 Luna

GPT-5.6 Luna lists cheapest GPT-5.6 tier for high-volume drafting and automation among its strengths; Inkling does not.

Fast, affordable execution while keeping respectable coding

GPT-5.6 Luna

GPT-5.6 Luna lists fast, affordable execution while keeping respectable coding among its strengths; Inkling does not.

Same 1M context and programmatic tool calling as its siblings

GPT-5.6 Luna

GPT-5.6 Luna lists same 1M context and programmatic tool calling as its siblings among its strengths; Inkling does not.

The first model release from Mira Murati's Thinking Machines Lab (ex-OpenAI CTO) - one of the most closely-watched new labs in AI

Inkling

Open weights make this possible at all — GPT-5.6 Luna is API-only, so it cannot leave the vendor's servers.

A 975B-parameter MoE (41B active) with native text, image, and audio reasoning in one model

Inkling

Mira Murati's Thinking Machines Lab debuts with Inkling - a 975B open-weight MoE with native multimodal reasoning and a dialable thinking-effort control — and its weights are open while GPT-5.6 Luna is API-only.

A dialable 'thinking effort' knob (0.2-0.99) that lets you trade speed for depth of reasoning per-request

Inkling

Mira Murati's Thinking Machines Lab debuts with Inkling - a 975B open-weight MoE with native multimodal reasoning and a dialable thinking-effort control — and it is the newer of the two.

Lowest cost at scale

Inkling

Its weights are open, so at volume you pay for your own hardware instead of GPT-5.6 Luna's $1/$6 per 1M tokens.

Which should you pick?

A cost-sensitive startup shipping high volume

Inkling

At Open weight (self-host / free) it undercuts GPT-5.6 Luna, and on millions of tokens that margin decides the monthly bill.

A team with data-privacy or self-hosting needs

Inkling

Open weights let you run it on your own hardware; GPT-5.6 Luna is API-only.

Anyone whose priority is cheapest gpt-5.6 tier for high-volume drafting and automation

GPT-5.6 Luna

It is specifically built for that.

Anyone whose priority is the first model release from mira murati's thinking machines lab (ex-openai cto) - one of the most closely-watched new labs in ai

Inkling

That is its strongest area.

GPT-5.6 Luna: where it fits

The budget, high-throughput GPT-5.6 tier — built for cheap, fast, large-volume work rather than deep long-context reasoning. Released July 9, 2026 by OpenAI, it is built for cheapest GPT-5.6 tier for high-volume drafting and automation, fast, affordable execution while keeping respectable coding, same 1M context and programmatic tool calling as its siblings, and high-throughput simple agentic jobs.

Its trade-offs are real: weak long-context recall deep in its 1M window (MRCR far below Sol), and lowest raw capability of the three GPT-5.6 tiers; no open weights. At $1 in / $6 out per million tokens, it sits in the budget price band.

Inkling: where it fits

Mira Murati's Thinking Machines Lab debuts with Inkling - a 975B open-weight MoE with native multimodal reasoning and a dialable thinking-effort control. Released July 15, 2026 by Thinking Machines Lab, it is built for the first model release from Mira Murati's Thinking Machines Lab (ex-OpenAI CTO) - one of the most closely-watched new labs in AI, a 975B-parameter MoE (41B active) with native text, image, and audio reasoning in one model, a dialable 'thinking effort' knob (0.2-0.99) that lets you trade speed for depth of reasoning per-request, and fully open weights (Apache 2.0) at frontier scale - unusual for a model this large and this new.

Its trade-offs: a brand-new lab's first release - no multi-generation track record yet, no official hosted API price - available via third-party hosts only at launch, and independent third-party benchmark verification is still limited given how recently it shipped. As an open-weight model, its running cost is your own hardware rather than a per-token fee.

The bottom line for this matchup

The defining split here is open vs. closed. Inkling gives you weights you control — self-host it, fine-tune it, keep data in-house, pay only for hardware. GPT-5.6 Luna gives you a managed, always-updated API with no infrastructure to run. Teams with GPUs, privacy requirements, or huge volume often favour the open model; teams that want zero ops and the latest capabilities favour the closed one. Capability is close enough that this operational question, not the benchmark, usually decides it.

Want both GPT-5.6 Luna and Inkling without two subscriptions? LumiChats gives you these plus 40+ models under one ₹69/day pass (about $1/day) — draft with one, cross-check with the other.

See pricing

Frequently asked questions

Is GPT-5.6 Luna or Inkling better for coding?

Public SWE-Bench figures are not available for either model, so the honest test is your own repository — run an identical real bug through both. By design, GPT-5.6 Luna leans toward cheapest gpt-5.6 tier for high-volume drafting and automation while Inkling leans toward the first model release from mira murati's thinking machines lab (ex-openai cto) - one of the most closely-watched new labs in ai, and that positioning usually predicts which feels better on your codebase.

Which is cheaper, GPT-5.6 Luna or Inkling?

Inkling is open-weight, so self-hosting means no per-token fee (you pay for hardware instead), while GPT-5.6 Luna is API-metered at $1/$6 per 1M tokens. For most teams without GPUs, the API model is cheaper to start; at very high volume, self-hosting can win.

Which has the bigger context window?

Both advertise 1M (~1,500 pages). Remember advertised ≠ usable: recall typically degrades before the ceiling.

Can I use both GPT-5.6 Luna and Inkling together?

Yes — a multi-model platform like LumiChats gives you GPT-5.6 Luna, Inkling and 40+ others under one ₹69/day pass (about $1/day), so you can draft with one and cross-check with the other instead of buying two subscriptions.

Which is newer, GPT-5.6 Luna or Inkling?

Inkling — released July 15, 2026, about 6 days after GPT-5.6 Luna.

Related comparisons

Specifications and benchmarks reflect publicly reported figures as of June 2026 and may change as providers release updates. Always verify on your own workload.