Flux.2 API pricing: Pro, Max, Flex and Klein per megapixel, and what one image really costs

Flux.2 is Black Forest Labs' December 2025 image family, and on UnificAlly it is the one image line billed per megapixel rather than per image: the balanced Flux.2 Pro API costs $0.021/megapixel, so a 1 MP image costs $0.021, a 2 MP image $0.042 and a 4 MP image $0.084. Five variants share one request shape and five different rates: Pro, Max, Flex, Klein 9B and Klein 4B. This post is the Flux 2 pricing breakdown for developers: how the megapixel meter turns into a per-image price at each resolution preset, what 100, 1,000 and 10,000 images cost a month on each variant, where Arena ranks them, how the rates compare with the per-image models on the platform, and the exact request the routes accept.

TL;DR: Flux.2 bills per megapixel of output on UnificAlly: Pro $0.021/megapixel, Max $0.049/megapixel, Flex $0.035/megapixel, Klein 9B $0.0105/megapixel and Klein 4B $0.0098/megapixel. At the default 1 MP preset those are the per-image prices; 4 MP costs four times as much. 1,000 Pro images at 1 MP cost $21; the same batch on Klein 9B costs $10.50. Our call: Pro is the production default, Klein 9B is the draft engine, and Max earns its rate only on final key art. On Arena's text-to-image board (October 7, 2026) the three big variants sit within 9 points of each other (Max 1162, Flex 1157, Pro 1153), so paying more than Pro buys the 5:4 ratio or the diffusion knobs, not a visibly better picture.

How much does the Flux.2 API cost?

Every Flux.2 route bills per megapixel of the finished image, and the resolution preset (0.6, 1, 2 or 4 MP) decides how many megapixels you buy. Reference images (up to 10 on any variant), the seven aspect ratios, the seed, and Flex's steps and guidance controls are all included in the rate. The rates below refresh from the live price list on every deploy.

Because the meter is linear, the per-image price is the rate times the preset. The table below is the one to budget from:

Two things to read off it. First, resolution is the biggest lever on a Flux.2 bill: a 4 MP Pro image costs what four 1 MP Pro images cost, so the preset should match the destination, not the ambition. Second, the Klein pair is priced far below the big three at every preset, which is why they exist: a 4 MP Klein 9B image costs less than a 1 MP Max image. Failed tasks are not billed. The pricing page lists every image model side by side.

Flux.2 cost per month at 100, 1,000 and 10,000 images

At the default 1 MP preset, monthly cost is count times rate. The table multiplies the live rates by three volumes; for 2 MP double the figures, for 4 MP quadruple them.

The workflow that makes the numbers small: draft on Klein 9B at 1 MP, lock the keepers with a seed, then re-render only those on Pro at the delivery preset. A team that drafts 1,000 images on Klein 9B and promotes 100 of them to Pro at 2 MP pays $10.50 plus $4.20, a fraction of 1,000 Pro images at 2 MP. Every variant takes the same prompt, aspect_ratio, resolution, image_urls and seed, so the promotion is a model-id change. There is no subscription and the balance does not expire.

Flux.2 Pro vs Max vs Flex vs Klein: what each rate buys

Arena's human-vote boards (text-to-image dated October 7, image edit October 6, 2026) put the three big variants in a tight band and the two Klein models a tier below:

The honest read: Max costs more than twice Pro for 9 Elo points on text-to-image, which the vote margins cannot distinguish, so its rate buys the 5:4 editorial ratio and a quality ceiling you will only see on final key art. Flex costs more than Pro for the diffusion knobs, worth it while you are sweeping a look and not after. Flux.2 Klein 9B is the surprise: on image edit it ties Flex at 1225 for a fraction of the rate, so for reference-guided edits it is the cheapest Flux.2 route with no quality penalty against the mid tier. Flux.2 Max and Flux.2 Flex stay on the shelf until a brief names what they add; Flux.2 Klein 4B is for thumbnail grids and local runs.

How Flux.2 pricing compares with per-image models

Per 1 MP (or 1K) image on UnificAlly today, with the text-to-image rank beside it:

Against that field, Flux.2 Pro is the mid-priced option with a mid-table rank, and Nano Banana 2.1 beats it on both price and rank at 1K. What Flux.2 keeps is the megapixel meter itself: a 0.6 MP thumbnail costs $0.0126 on Pro, a size the per-image models cannot discount, and a 4 MP native render costs $0.084 with no upscale step. If the pipeline needs many small images or a few very large ones, the meter works in your favour; if everything is 1K, test Nano Banana 2.1 first.

How to call Flux.2 at the price you planned

One API key, POST /v1/tasks, and resolution set to the preset you priced above. This is the request from the Flux.2 Pro docs page, a 2 MP portrait billed at $0.042 when it completes.

curl -X POST https://api.unifically.com/v1/tasks \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -d '{
    "model": "black-forest-labs/flux.2-pro",
    "input": {
      "prompt": "A photorealistic portrait of a woman in golden hour light",
      "aspect_ratio": "9:16",
      "resolution": "2mp"
    }
  }'

Change resolution to 1mp for the default rate or 0.6mp for thumbnails, add image_urls with up to 10 references at no extra charge, and swap the model id for black-forest-labs/flux.2-klein-9b to draft or black-forest-labs/flux.2-max to finish. The response returns a task_id; poll GET /v1/tasks/<task_id> or set callback_url. Full field reference: docs.unifically.com/models/image/flux/flux.2-pro.

Flux.2 Pro FAQ

How much does the Flux.2 Pro API cost?

Flux.2 Pro costs $0.021/megapixel on UnificAlly, billed on the finished image: $0.021 at the default 1 MP preset, $0.042 at 2 MP and $0.084 at 4 MP. Reference images, aspect ratio and seed are included. Failed tasks are not billed.

What does a Flux 2 image cost at 1 MP?

Flux.2 Pro $0.021, Max $0.049, Flex $0.035, Klein 9B $0.0105 and Klein 4B $0.0098. Multiply by 2 for the 2 MP preset and by 4 for 4 MP.

What do 1,000 Flux.2 images cost a month?

At 1 MP, $21 on Pro, $49 on Max, $35 on Flex, $10.50 on Klein 9B and $9.80 on Klein 4B. Drafting on Klein 9B and promoting keepers to Pro keeps a mixed month close to the Klein figure.

Is Flux.2 Max worth more than Pro?

On Arena's text-to-image board (October 7, 2026) Max scores 1162 and Pro 1153, a 9-point gap inside the vote margins, while Max costs more than twice the Pro rate per megapixel. Max adds a 5:4 aspect ratio and is tuned for maximum quality on final key art; for everything else Pro is the better buy.

How much does Flux 2 Klein 9B cost?

$0.0105/megapixel, so $0.0105 per 1 MP image and $0.042 at 4 MP. It takes the same prompt, aspect ratio, resolution, reference images and seed as Pro, without the Flex-only steps and guidance controls, and on Arena's image-edit board it ties Flex at 1225.

What is the cheapest way to try the Flux.2 API?

New UnificAlly accounts get a $0.50 signup balance, enough for 23 Flux.2 Pro images or 47 Klein 9B images at 1 MP, with no subscription. After that, billing is pay-per-use and the balance never expires.

What will change this post

We will update the rate tables when Black Forest Labs changes the Flux.2 rates or adds a variant, when Flux 3 image models reach the platform and take the headline row, and when the Flux.2 rows move on Arena by enough to change the ordering above. Prices on this page refresh from the live price list on every deploy, so the tokens stay current between those updates.

Related reading on Flux.2 Pro

• Flux.2 Pro API, Flux.2 Klein 9B API and Flux.2 Max API: playgrounds, parameters, FAQs.
• Nano Banana 2 API pricing: Google's per-image rate card at 1K, 2K and 4K.
• GPT Image 2 API pricing: the flat per-image rate at the top of the Arena board.
• Qwen Image 2.0 API pricing: Alibaba's flat-rate image line.