How similar are narrow-line Seyfert 1 galaxies and high redshift AGN ?

The recent observation of highly accreting supermassive black holes (SMBH) at very high redshift (>4) with the James Webb Space Telescope (JWST) allowed us to shed light for the very first time on the early evolutionary phases of active galactic nuclei (AGN). Perhaps unsurprisingly, several of the physical properties observed in these new objects, especially those known as little red dots (LRDs), are closely reminiscent of the low-mass and high-Eddington AGN in the local Universe, and in particular of the class of narrow line Seyfert 1 (NLS1) galaxies. However, some differences also emerged, likely due to the radically different environment where LRDs and NLS1s live. In this talk, I will review the multiwavelength properties of local NLS1s, and compare them with those found at high-z, showing that despite some differences, the study of NLS1s can be extremely useful to better understand the physics of high-z quasars and the early-stages of AGN evolution