Extracellular vesicles (EVs) have great promise in developing diagnostics and prognostics of disease, owing in part to the possibility of tracing individual EVs back to a cell of origin. Realising this aspect of the potential of EVs, however, may require more sensitive characterisation methods than are currently widely available, including single-particle characterisation. In this presentation, we review results of an evaluation of four platforms that use orthogonal methods to size, count, and phenotype EVs. Both biological EVs and synthetic EV mimetics (hollow silica beads) were tested on all platforms. The ParticleMetrix ZetaView uses optical methods to perform single particle tracking (nanoparticle tracking analysis, NTA) in scatter and fluorescence modes. The NanoView ExoView captures particles on a surface by immunoaffinity, then images particles by single-particle interferometric reflectance imaging sensing (SP-IRIS) and optional fluorescence detection. The Spectradyne nCS1 is a resistive pulse sensing (RPS) instrument that measures particles in one of four size ranges using a disposable insert for each sample. Finally, the NanoFCM Flow Nanoanalyzer (nFCM) is a flow-based instrument that detects nano-sized particles by scatter and fluorescence. Using two well-characterised EV populations that display different ratios of CD63 and CD81, RPS and nFCM returned similar particle concentrations, while NTA readings were approximately one order of magnitude lower. SP-IRIS does not measure concentrations. RPS, nFCM, and SP-IRIS indicated similar size profiles, with smaller particles predominating but with detection dropping off below 50-60 nm in diameter. For phenotyping, both nFCM and SP-IRIS (in fluorescence mode) could indicate at least two antigens on the same particle. RPS cannot currently phenotype using fluorescence, and fluorescent NTA cannot currently detect more than one wavelength with the same particle population. Additionally, we were able to obtain signal for only one antigen, CD81, using fluorescent NTA. Finally, using a mixture of four distinct sizes of silica nanoparticles, RPS, nFCM, and SP-IRIS, but not NTA, were able to distinguish at least three of the four populations. Based on the results of this evaluation, we draw conclusions about current single-particle analysis capabilities that can be improved and expanded upon to grasp the full potential of EV biomarkers.