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Black Forest Labs (FLUX)

Black Forest Labs · Ranked #6 of 7 in Image Generation APIs

67.4/ 100
CSolid

Maker of the FLUX models offering a first-party REST API with async polling and megapixel-based pricing; powerful models but leaner API ops and no published SLA.

Best for

First-party FLUX.2 generation + editing

Screenshot of Black Forest Labs (FLUX)

Overview

Black Forest Labs (BFL) is a Freiburg, Germany-based foundation-model lab founded in 2024 by former Stability AI researchers (including original Stable Diffusion authors Robin Rombach, Andreas Blattmann and Patrick Esser). Its FLUX family of rectified-flow transformer models has become one of the most widely deployed image-generation systems in production, powering or available through Adobe, Canva, Meta, Microsoft Azure AI Foundry, Vercel, ElevenLabs, and the major inference clouds (fal.ai, Replicate, Together AI). The company sells access two ways: a metered, pay-per-image hosted API at bfl.ai/docs.bfl.ai (1 credit = $0.01, no subscriptions or seat fees), and open-weight model releases (FLUX.1 [dev]/[schnell], FLUX.1 Kontext [dev], FLUX.2 [dev]/[klein]) under separate self-host commercial licenses. In late 2025 BFL raised a $300M Series B at a $3.25B valuation, co-led by Salesforce Ventures and a16z's Anjney Midha with NVIDIA, General Catalyst and Temasek participating.

The API's strongest selling points are frontier quality at aggressive pricing and a strong editing story. On the Artificial Analysis Text-to-Image Arena, FLUX.2 [pro] launched at #2 (trailing only Google's Nano Banana Pro) while costing under a quarter of that model's price, and FLUX.1 Kontext introduced fast in-context editing (BFL claims ~0.9s per 1024x1024 edit, roughly 8x faster than diffusion-based editors and GPT-Image on equivalent hardware). The lineup is unusually broad, text-to-image, instruction editing, multi-reference (up to 10 input images on FLUX.2), inpainting/outpainting, eraser/VTO tools, and structural control (Canny/Depth/Redux), and the dual open-weight + API model lets teams prototype locally and scale on the hosted endpoint or any third-party cloud.

The main friction points are operational rather than quality-related. Developers repeatedly report an aggressive, opaque content-moderation layer on the hosted API that returns "Request Moderated" / "Content Moderated" errors on requests they consider benign, with limited recourse, a recurring complaint in the official GitHub issue tracker. The API is asynchronous/poll-based (submit a job, poll for the result) rather than a single synchronous call, FLUX.2 [pro] uses variable megapixel-based pricing that makes per-image cost harder to predict, and there is no official multi-language SDK, integration is via the raw REST API plus community libraries, and the open-weight tooling/fine-tuning ecosystem is still thinner than Stable Diffusion's. Buyers prioritizing photorealism, editing, and cost-efficiency get excellent value; those needing permissive moderation, deterministic synchronous latency, or first-party SDKs should weigh those gaps.

How this score is derived

The APIbenchmarks Index is a weighted sum of four dimensions, each scored on an absolute 0–100 reference scale. See the methodology for every mapping.

DimensionScoreWeightContribution
Documentation & DXClean, model-organized docs at docs.bfl.ai with a playground, quick-start and per-model pricing, but light on first-party SDK references and endpoint-level detail, leaning on REST examples and third-party guides.
72
30%21.6
ReliabilityFLUX powers production workloads at Adobe, Canva, Meta and Azure and is mirrored across fal.ai/Replicate/Together, but BFL publishes no public status page or SLA for its own bfl.ai API, so uptime is undisclosed.
66
25%16.5
Ecosystem & SDKsVery strong adoption via open weights (top Hugging Face downloads) and broad availability across every major inference cloud and ComfyUI, though native fine-tuning/tooling is still less mature than Stable Diffusion's.
58
25%14.5
AccessibilityEasy onboarding (credit top-ups, no subscription, browser playground, MCP integration), but the aggressive content-moderation filter and async poll-based flow add real friction for some legitimate use cases.
74
20%14.8
APIbenchmarks Index (ABI)67.4

Table 1. Derivation of the ABI for Black Forest Labs (FLUX). Contribution = score × weight; the index is their sum.

At a glance

Vendor
Black Forest Labs
Pricing model
Per megapixel, credit-based ($0.015-0.07/MP)
Free tier
No
Official SDKs
7 languages

Pricing

FLUX.2 [pro]from $0.03/imageMegapixel-based pricing; flagship T2I + editing, up to 10 reference images. Launched #2 on Artificial Analysis T2I Arena.
FLUX.2 [flex]from $0.05/imageMegapixel-based; tunable quality/steps variant of FLUX.2.
FLUX1.1 [pro]$0.04/imagePrevious-gen flagship text-to-image, fixed per-image price.
FLUX1.1 [pro] Ultra$0.06/imageUp to 4MP output with optional 'raw' photorealistic mode.
FLUX.1 Kontext [pro]$0.04/imageFast in-context image editing, ~0.9s per 1024x1024 edit.
FLUX.1 Kontext [max]$0.08/imageHighest-quality editing tier with improved typography and prompt adherence.

Key features

  • Text-to-image generation (FLUX.2 / FLUX1.1 pro / Ultra)
  • In-context image editing via FLUX.1 Kontext (text + image prompting)
  • Multi-reference editing, up to 10 input images on FLUX.2
  • Inpainting and outpainting (FLUX Fill / Outpainting)
  • Object removal (FLUX Eraser) and virtual try-on (FLUX VTO)
  • Structural conditioning: Canny edges, Depth, and Redux variation tools
  • 'Raw' photorealistic mode and up to 4MP output on Ultra
  • Browser-based playground for instant model testing
  • MCP (Model Context Protocol) integration for use inside Claude and other agents
  • Open-weight model releases for self-hosting under commercial license tiers

Official SDKs

REST API (HTTP)Python (community / examples)Official inference repo on GitHub (PyTorch)Hugging Face Diffusers integrationComfyUI nodesMCP serverThird-party access via fal.ai, Replicate, Together AI, NVIDIA NIM, Azure AI Foundry

Strengths & trade-offs

Strengths
  • +Frontier image quality at low cost, FLUX.2 [pro] launched #2 on the Artificial Analysis T2I Arena while costing under a quarter of the top model
  • +Fast in-context editing: FLUX.1 Kontext averages ~0.9s per 1024x1024 edit, ~8x faster than diffusion-based editors per BFL
  • +Pure pay-per-image metering (1 credit = $0.01), no subscriptions, seats or minimums
  • +Broad capability set: text-to-image, instruction editing, multi-reference (up to 10 images), inpainting/outpainting, eraser, VTO, and Canny/Depth/Redux control
  • +Open-weight releases (dev/schnell/klein) allow local prototyping and self-hosting alongside the hosted API
  • +Wide third-party availability, fal.ai, Replicate, Together AI, NVIDIA NIM and Azure AI Foundry, avoids single-vendor lock-in
Trade-offs
  • Aggressive, opaque content moderation: developers report frequent 'Request Moderated' errors on requests they consider valid
  • No official multi-language SDK, integration is raw REST plus community libraries
  • Asynchronous poll-based API (submit then poll) rather than a simple synchronous call adds integration complexity
  • FLUX.2 [pro]/[flex] use variable megapixel-based pricing, making exact per-image cost harder to predict
  • No public status page or SLA for the bfl.ai API; uptime guarantees are undisclosed
  • Open-weight fine-tuning and tooling ecosystem is still thinner than Stable Diffusion's

What developers say

Developers praise FLUX's image quality, editing speed and open-weight access, but the most common complaint is the hosted API's overly aggressive, opaque content moderation.

Seeing a lot of this in the API... really for requests that should be totally fine/valid.

Key figures

Text-to-Image Arena Elo (FLUX.2 [pro])1186.7 (rank 13 of 83)Artificial Analysis
Launch rank, T2I Arena (FLUX.2 [pro])#2, behind only Nano Banana ProArtificial Analysis
Image edit latency (FLUX.1 Kontext [pro])~0.9s per 1024x1024 edit (~8x faster than diffusion editors)Black Forest Labs (Kontext launch)
Price per image (FLUX.2 [pro])from $0.03BFL pricing docs
Price per image (FLUX1.1 [pro] Ultra)$0.06BFL pricing docs
Price per image (FLUX.1 Kontext [max])$0.08BFL pricing docs

Compare Black Forest Labs (FLUX) head to head

Sources

  1. https://bfl.ai/pricing
  2. https://docs.bfl.ml/quick_start/pricing
  3. https://artificialanalysis.ai/image/models/flux_flux-2--pro
  4. https://x.com/ArtificialAnlys/status/1995924695775150409
  5. https://bfl.ai/blog/flux-1-kontext
  6. https://github.com/black-forest-labs/flux/issues/464
  7. https://github.com/black-forest-labs/flux/issues/489
  8. https://bfl.ai/blog/our-300m-series-b
  9. https://github.com/black-forest-labs/flux

Figures last verified 2026-06-27. Spotted an error? corrections@apibenchmarks.com