Better than the city's own reputation lets it admit. Nine in ten graded settings are good or better. Two are outstanding. Primary maths comes in above the national benchmark. A city that will happily tell you it is rough has quietly been getting the schools right, and nobody involved seems keen to make a fuss about it.
At primary level there are 37 mainstream state primaries in the area, and their key stage two maths average sits at around 103 against a national benchmark of 100. That is not a dramatic gap, and anyone selling you a postcode on the strength of it is overselling. What it does say is that the average Portsmouth primary is doing slightly better than the average English one, across a lot of schools rather than one or two flagships pulling the mean up. The spread runs the whole island and the mainland edge: Craneswater Junior School and Fernhurst Junior School in the south, Copnor Primary School and Milton Park Primary School through the middle, Stamshaw Infant Academy and Portsdown Primary School toward the north. Several sites still run split infant and junior schools, which means two admissions events rather than one, and is worth knowing before you fall in love with a street.
Secondary is the flatter picture. Across the 11 mainstream state secondaries in the area, the pupil-weighted Attainment 8 score comes out at around 41. That is a middling number and it deserves to be described as one. It also covers schools with genuinely different intakes and characters, from Admiral Lord Nelson School and Miltoncross Academy in the east to Priory School and Trafalgar School closer to the centre, plus a university technical college in the mix. Reading one average across eleven schools tells you almost nothing about the one your child would actually attend.
The inspection picture is where the answer gets emphatic. Ofsted has published an overall effectiveness grade for 22 settings across the Portsmouth local authority, and 20 of those are good or better. Two are outstanding, one requires improvement, and one is inadequate. That is roughly nine in ten graded settings meeting the bar, which is a strong return for any city and a very strong one for a city that spent the late 2000s being told publicly how badly it was doing. Those counts cover the whole local authority rather than any single neighbourhood, so they describe the system rather than your street. A further 27 settings hold no published overall grade yet, which means exactly that and nothing more: not graded is not the same as not good.
The usual warning applies with more force here than in most places. Naming a school is not the same as getting into it. Portsmouth is dense, the schools sit close together, and admission runs on the authority's own criteria rather than on the estate agent's map of what is walkable. A street that sits between two popular schools can end up allocated to neither. Check the current admissions arrangements and last year's actual allocation distances for the specific address before you let a school name influence what you offer on a house, because the school you are picturing and the school you are entitled to are decided by a formula that does not care how much you liked the front garden.
The schools are one of the genuinely strong reasons to be here, and unlike the seafront or the price, it is the part of Portsmouth's case that nobody thought to put on a poster.