Same fabric weight, same message, five dollars apart, and people agonize over it anyway. Here's the actual difference, including the cases where one of them is simply the wrong buy.
Warmth
The hood is worth more than the fabric weight suggests. Both sit around the same 8oz fifty-fifty cotton-poly blend, so on paper they're equivalent, but a hood traps heat at the neck and gives you somewhere to go when the wind picks up. For standing still outdoors at a picket line, a polling place, or a demonstration in November, the hoodie wins clearly.
Indoors the hood becomes bulk you're carrying for no reason, and it sits awkwardly under a coat collar. If most of your wear is inside, the crewneck is the more comfortable garment.
Where you can wear it
This is the deciding factor for more people than warmth is.
A crewneck reads as a sweater. It goes into a staff room, a parents' evening, a clinic break room, and a meeting where you'd rather not be the person in a hoodie. A hoodie reads as casualwear almost everywhere, fairly or not.
If you work somewhere with a dress code, or you're buying for a teacher, a nurse, or anyone whose workplace is watchful, buy the crewneck. The embroidered Silence Is Not Neutral crewneck takes this furthest. The phrase is stitched rather than printed, so it reads as texture rather than slogan from across a room.
How the message reads
A crewneck gives you a flat, uninterrupted chest panel. A hoodie gives you the same panel with a pocket below it and a drawcord crossing the top of it. For a short phrase in heavy type it makes little difference. For anything with more than a few words, the crewneck is measurably more legible.
There's also the practical matter that a hood bunches at the shoulders, which can angle the print slightly in photographs. If you're ordering for a group specifically so the message reads in photos, crewnecks photograph more consistently.
Price and sizing
Crewnecks here run $42.99 to $49.99, hoodies $47.99 to $52.99. Both are unisex and true to size. The one sizing note worth knowing: if you like a roomier fit, size up in the hoodie rather than the crewneck, because the crewneck's tubular knit body already sits fairly relaxed through the middle.
The oversized-fit Organize or Comply hoodie is cut about two inches wider with a dropped shoulder if you want that look deliberately rather than by accident.
When each one is the wrong buy
Don't buy the hoodie if the person mostly works indoors in a role with a dress code. It'll sit in a drawer.
Don't buy the crewneck if the intended use is outdoor and cold. You'll wish you had the hood by the second hour.
And don't buy either as a first purchase for someone whose size you're guessing at. A tote or a mug costs less and can't be the wrong size, and there's a full measurement chart on the FAQ page for when you do commit.
The short version
Outdoors and cold, buy the hoodie. Work and indoors, buy the crewneck. Buying for a group that wants to photograph well, buy crewnecks. Buying for someone in a watchful workplace, buy the embroidered crewneck.
Every message line carries both, in shared colorways, so a mixed group order stays consistent: Defend Democracy, Organize or Comply, Silence Is Not Neutral, and Comfort Is a Slow Death. SPEAKUP10 takes 10% off, and everything is printed to order in the USA, so allow about a week.
Related reading
If you are buying for a specific day outdoors, What to Wear to a Protest covers the rest of the kit, and How to Wash a Printed T-Shirt covers keeping either one looking new.