Black Forest Labs released Flux 2 Dev and Flux 2 Pro simultaneously in January 2025, offering developers a clear choice: excellent quality at a reasonable price, or premium quality for those who need the absolute best. Unlike the Schnell vs Dev comparison where speed is the primary trade-off, here both models are relatively slow—the difference is purely about output quality.
Flux 2 Dev is the open-weight version, meaning its weights are publicly available for researchers and developers to fine-tune and customize. Flux 2 Pro is proprietary and closed-source, with Black Forest Labs retaining exclusive control over the model. This distinction matters less for API users—both models are accessed the same way—but it explains why Pro can achieve slightly higher quality while keeping certain optimizations private.
The cost difference is substantial: Pro costs about 2.5x more than Dev. That's a significant premium for what benchmarks suggest is a modest quality improvement. The ELO gap (~1143 for Dev vs ~1170 for Pro) confirms this—both are strong performers, but Pro edges ahead in blind comparisons.
Both models support image-to-image generation and produce excellent prompt adherence. The practical question is whether Pro's refinements in detail, coherence, and color accuracy justify the premium for your specific use case.
Note: Both models are available through ImageGPT's quality routes. Flux 2 Dev anchors the "quality/balanced" route, while Flux 2 Pro appears in the "quality/high" route for maximum quality.