FLUX.2 Flex API

Introduction

FLUX.2 [flex] Text to image is Black Forest Labs' FLUX.2 model for lettering and layout, released on 25 November 2025. It turns a written prompt into a picture, writes quoted text into it as spelled, follows hex colour codes, and renders at 1k or 2k in nine shapes.

Choose a mode by starting material

Key features

Lettering that comes back as written

In our tests a film poster with a title, a tagline and a release line, an album cover with a script title, and a tea-tin label all came back with every quoted line spelled correctly.

Colour by hex code

Write a code next to a large object, a backdrop or the grade and the render stays close to it. On very small lettering the shade can drift.

Two size tiers, nine shapes

1k is about one megapixel and 2k renders 2048 pixels on the long side, from 21:9 banners to 9:21 stories.

Request parameters

Pricing

Prices are in credits, the same credits you use on the website (1 credit = $0.01). The hold is taken when the task is accepted and settled to the actual charge when it finishes; failed tasks are refunded.

Each task is rounded up to whole credits, so one run at the lowest tier costs 9 credits per image ($0.09).

For an exact number before you run, send the same body to POST /jobs/quote.

Use cases

Posters and covers

Film posters, album covers and magazine mastheads where the type is part of the design.

Packaging and product shots

Labels, tins and bottles in specific brand colours, photographed in a styled setting.

Advertising headlines

A headline and a line of copy placed over a lit scene, ready for a pitch or a first layout.

Prompt guide & pro tips

Quote and place every line

Put each line of text in quotes and say where it sits. End with "No other text" to stop extra words from appearing.

Give colours as codes

Name the object and the hex value together, for example a label in cream #F3E9D2 with a gold #C9A227 border.

Describe people by clothing and pose

Say what each person wears, where they stand and where they look.

Start at 2k for type

Larger sizes give small lettering more pixels, which helps legibility. Use 1k for quick drafts.

Expect 20 to 90 seconds

Most requests finished in that range in our tests; a busy queue takes longer.

API quick start

Call the FLUX.2 Flex API in three steps

1. Create an API key. Sign in to PopNow and create a key in the API console. Keys start with sk-popnow- and use the same credits as the website.
2. Send the request. POST /jobs/createTask with model black-forest-labs/flux-2-flex/text-to-image and an input object that follows the parameter table. The response returns a task ID straight away.
3. Get the result. Poll GET /jobs/recordInfo with the task ID, or pass a callBackUrl and we post the result to it. Download the output links when the task succeeds.

# 1. Create the task. Keep the Idempotency-Key if you retry after a network error.
export IDEMPOTENCY_KEY="$(uuidgen)"
curl -X POST https://api.popnow.ai/api/v1/jobs/createTask \
  -H "Authorization: Bearer $POPNOW_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: $IDEMPOTENCY_KEY" \
  -d '{
  "model": "black-forest-labs/flux-2-flex/text-to-image",
  "input": {
    "prompt": "A ceramic teapot on a linen cloth, soft window light, muted palette",
    "aspect_ratio": "1:1",
    "resolution": "1k"
  }
}'

# 2. Copy data.taskId from the response, then poll until state is succeeded, failed, canceled or expired.
TASK_ID="TASK_ID_FROM_RESPONSE"
curl "https://api.popnow.ai/api/v1/jobs/recordInfo?taskId=$TASK_ID" \
  -H "Authorization: Bearer $POPNOW_API_KEY"

Replace the prompt and any links with your own. The API tab has the response, polling and callback reference.

FLUX.2 Flex API questions

All FLUX models

FLUX.2 Pro is quicker and cheaper for photographic work with lighter text.

• FLUX.2 Max APITop-tier FLUX: photoreal light and exact brand colorsFrom 11 credits per image
• FLUX 3 APIVideo with synced sound and a quick draft tierFrom 45 credits for a 5-second clip
• FLUX.2 Klein 9B LoRA APIFast FLUX.2 Klein 9B that loads up to three of your LoRAsFrom 3 credits per image
• FLUX.2 Klein Base 9B LoRA APIUndistilled Klein 9B for varied looks with your LoRAsFrom 4 credits per image
• FLUX.2 Klein 4B LoRA APISmall, quick FLUX.2 Klein 4B with your own LoRAsFrom 3 credits per image
• FLUX.2 Klein Base 4B LoRA APIUndistilled Klein 4B that loads your own LoRAsFrom 3 credits per image
• FLUX.2 Klein 9B APIFast FLUX edits that keep faces and poses intactFrom 2 credits per image
• FLUX.2 Klein 4B APIThe smallest, quickest FLUX for rapid draftsFrom 2 credits per image
• FLUX.2 Dev LoRA APIFLUX.2 Dev images and edits with your own LoRAsFrom 4 credits per image
• FLUX.2 Pro APIPhotoreal images with readable text and hex color controlFrom 5 credits per image
• FLUX.2 Flex APISpells headlines and labels exactly as writtenFrom 9 credits per image
• FLUX.2 Dev APIOpen-weights FLUX that can merge people into one sceneFrom 2 credits per image
• FLUX.1 Krea Dev LoRA APIPhotographic FLUX.1 Krea with your own LoRAsFrom 4 credits per image
• FLUX.1 Dev ControlNet LoRA APIPose, depth or edge control on FLUX.1 with your LoRAsFrom 6 credits per image
• FLUX.1 Fill Dev LoRA APIMasked inpainting on FLUX.1 Fill with your own LoRAsFrom 7 credits per image
• FLUX.1 Dev LoRA APIClassic FLUX.1 Dev with up to three of your LoRAsFrom 3 credits per image
• FLUX.1 Schnell LoRA APIFast FLUX.1 Schnell that loads your own LoRAsFrom 1 credit per image

Other image APIs

• Nano Banana 2.1 APIGoogle's newest Nano Banana, sharp text and 4K outputFrom 8 credits per image
• Nano Banana Pro APIPlans the layout first: dense text, diagrams and 4K editsFrom 17 credits per image
• GPT Image 2.5 Sunburst APIOpenAI's quality-first model, up to 4K with clean textFrom 1 credit per image
• Seedream 5.0 Pro APIHigh-detail images and edits from up to ten referencesFrom 6 credits per image
• Qwen Image 2.1 Pro APIUp to six detailed 2K images from one promptFrom 6 credits per image
• Qwen Image 2.1 Turbo APIFast 8-step renders, up to six per promptFrom 3 credits per image

More about FLUX.2 Flex

Try it

FLUX.2 Flex AI Image Generator onlineCreate images with FLUX.2 Flex in PopNow

Docs

FLUX.2 Flex model ID and input schema in the API docsPopNow API quickstart: your first request in five minutesImage generation guide for the PopNow APIWebhooks: get FLUX.2 Flex results without polling