Flux Kontext: edit an image with a single sentence
Regular generation "based on" a source image often redraws the whole picture: the background changes, but the face and pose drift along with it. Flux Kontext — editing models from Black Forest Labs (the team behind the Flux line and, before that, Stable Diffusion) — takes a different approach: you upload an image and write an instruction, and the model changes only what you asked for. Everything else stays untouched.
Both versions are available on NeuralBox: Kontext Pro at $0.042 and Kontext Max at $0.083 per edit — no separate BFL account, pay by card or crypto. This post covers what the model can do and which instructions to start with.
How it works
Upload one reference image and describe the edit in words: "replace the text on the sign", "make it night", "put a red jacket on him". Kontext localizes the change and preserves the composition, faces and details — that's what sets it apart from ordinary image-to-image.
8 aspect ratios are supported, including cinematic 21:9, so you can prepare the result for its destination right away — from a square for social media to a wide banner.
What you can edit: example instructions
An instruction is one sentence. The more specific it is, the more precise the edit; it helps to add "keep everything else as it is" explicitly.
Pro or Max: pricing
Prices are on the Basic plan ($5 = 150,000 tokens); on higher plans tokens are up to 40% cheaper. Pro covers typical edits; choose Max for complex instructions and better preservation of fine details.
| Model | Price per edit | When to use |
|---|---|---|
| Flux Kontext Pro | 1,250 tokens ≈ $0.042 | Typical edits: background, text, time of day, clothing |
| Flux Kontext Max | 2,500 tokens ≈ $0.083 | Complex edits and maximum detail preservation |
How to try it
Sign in with Telegram, Google or email, top up your balance (from $5 by card, from $2 in crypto), open the Images tab and select Flux Kontext Pro. Upload an image (one reference image, up to 50 MB), write the instruction — the edit is ready in a few seconds. Didn't get it right the first time? Refine the wording: at $0.042 an iteration costs next to nothing.
A full overview of the Flux 2 line (Pro, Flex, Kontext), prompt examples and an FAQ are on the Flux 2 on NeuralBox page.