Flux 2 Flex Text to Image
bfl/flux-2/flexFlux 2 Flex is BFL's advanced text-to-image AI model. Create photorealistic images, illustrations, and concept art from natural language descriptions with exceptional detail and prompt adherence.
- Base price
- $0.06USD / run
- Execution
- async
- Model type
- image
- Input fields
- 6
Try the model
Playground
Examples
Select an example to load its inputs and result into the playground.
Model card
Specifications
Pricing
- Base price
- $0.06 / run
Context & modalities
- Input
- Schema-defined
- Output
- image
Capabilities
- Chat
- Not supported
- Vision
- Not supported
- Reasoning
- Not supported
- Structured output
- Not supported
- Function calling
- Not supported
- Audio input
- Not supported
Access
- Provider
- BFL
- Model ID
- bfl/flux-2/flex
- Execution
- async
- Base URL
- https://api.sandbase.ai
- API
- Unified Run API
- Endpoint
- /v1/run
Human preference
Arena
Elo ratings from blind side-by-side votes, compared with other image and video models.
Rankings sourced from Artificial Analysis Arena
- Leaderboard
- Text to Image
- Rank
- #29 of 106
- Elo
- 1026 ±11
- Gap to #1
- −196
Text-to-image arena: people pick the better of two images generated from the same prompt, without seeing the model names.
- #24Krea 2 Large1034±9
- #25Qwen Image 2.0 Pro (2026-04-22)1030±11
- #26MAI-Image-2.5-Flash1029±11
- #27Qwen-Image-2.1-Turbo1029±12
- #28Wan 2.6 Image1027±12
- #29FLUX.2 [flex]1026±11
- #30Ideogram 4.0 (Quality)1026±10
- #31Recraft V4.1 Utility1026±11
- #32Seedream 4.51026±12
- #33Luma UNI 1 Max1023±12
API README
Flux 2 Flex Text to Image
FLUX.2 [flex], the tunable tier: adjust steps and guidance for typography-heavy or detailed work. Text to image.
Fields
| Field | Type | Default | Notes |
|---|---|---|---|
prompt | string, required | — | Text instruction. |
guidance_scale | number 1.5–10 | 3.5 | How strictly to follow the prompt. |
num_inference_steps | integer 2–50 | 28 | More steps add detail and time. |
output_format | jpeg / png | jpeg | Output file format. |
aspect_ratio | 21:9 / 16:9 / 3:2 / 4:3 / 5:4 / 1:1 / 4:5 / 3:4 / 2:3 / 9:16 | 16:9 | Output shape. |
seed | integer | random | Fix it to compare prompt changes. |
Billing
$0.06 per image.
| Request | Price |
|---|---|
| One image | $0.06 |
Failed runs are not charged.
Prompting
- Write subject, setting, composition, style, then light.
- Quote any text that must appear.
Limits
- One output image per request.
Also on SandBase
Other FLUX.2 endpoints: bfl/flux-2/max, bfl/flux-2/pro, bfl/flux-2/dev, bfl/flux-2/turbo, bfl/flux-2/flex/edit.
Start building
Send your first request
OpenAI-compatible endpoint with unified authentication and usage tracking.
# The quoted heredoc keeps Unicode and shell metacharacters unchanged.
result=$(curl --fail-with-body --silent \
-X POST "https://api.sandbase.ai/v1/run" \
-H "Authorization: Bearer $SANDBASE_API_KEY" \
-H "Content-Type: application/json" \
--data-binary @- <<'SANDBASE_JSON'
{
"model": "bfl/flux-2/flex",
"prompt": "A high-quality 3D render of a cute fluffy monster eating a giant donut; the fur simulation is incredibly detailed, the donut glaze is sticky and reflective, bright daylight lighting, shallow depth of field.",
"aspect_ratio": "16:9",
"output_format": "jpeg",
"guidance_scale": 3.5,
"num_inference_steps": 28
}
SANDBASE_JSON
)
run_id=$(printf '%s' "$result" | jq -r .id)
for attempt in $(seq 1 120); do
status=$(printf '%s' "$result" | jq -r .status)
case "$status" in completed|failed|timeout) break ;; esac
sleep 2
result=$(curl --fail-with-body --silent \
-H "Authorization: Bearer $SANDBASE_API_KEY" \
"https://api.sandbase.ai/v1/run/$run_id")
done
status=$(printf '%s' "$result" | jq -r .status)
[ "$status" = completed ] || { echo "Generation ended: $status" >&2; exit 1; }
printf '%s\n' "$result"Choose your model
Compare models
| Model | Type | Default price | Released |
|---|---|---|---|
Flux 2 Flex Text to ImageThis model BFL | Image | $0.06 / run | Nov 25, 2025 |
BFL | Image | $0.05 / run | Oct 1, 2026 |
BFL | Image | $0.05 / run | Oct 1, 2026 |
BFL | Image | $0.02 / run | Jan 15, 2026 |
BFL | Image | $0.02 / run | Jan 15, 2026 |
BFL | Image | $0.01 / run | Jan 15, 2026 |
Questions
FAQ
How do I call BFL Flux 2 Flex Text to Image through SandBase?
Create a SandBase API key, then send requests with the model ID "bfl/flux-2/flex" to Unified Run API (/v1/run) at https://api.sandbase.ai. The request examples on this page show the exact payload.
Do I need a separate BFL account?
No. One SandBase API key and balance gives you access to BFL Flux 2 Flex Text to Image and the other models in the catalog; you do not need to sign up with BFL separately.

