Rapid methods for the detection of contaminants and biochemical markers are needed in many areas such as environmental monitoring, food and beverage testing, and medical diagnosis. On-site analysis in particular is becoming a key component of safety and quality monitoring, when costs, equipment, or time limitations does not allow the use of conventional laboratory techniques. Centred around the needs for fast results, scalable fabrication, and ease-of-use, a new platform called FiberLab is developed: a low-cost multicapillary-format test capable of collecting and analysing µL-sized sample by colorimetric chemical assays. Most approaches rely on cumbersome fabrication process based on the chemical post-modification of capillaries but, thanks to the thermal drawing facility, is it possible to produce ready-to-use lab-in-fiber tests at large scale and low cost.