Enter your item and see, side by side, what you keep and what your buyer pays on each site. A lower total for the buyer usually means a quicker sale.
Vinted says its fee is "usually 3% to 8% + £0.30 to £0.80". We use 5% + £0.70 as a typical figure. Check your own Vinted checkout and change it here if yours differs.
If you're selling your own things as a private seller in the UK, neither eBay nor Vinted takes anything from your sale. Both charge the buyer a Buyer Protection fee instead. So the real question isn't what you keep, it's how much the buyer has to pay, because that decides how competitive your price looks.
On private sellers' listings eBay adds a flat 10p per item, plus 7% of the price up to £20, 4% of the part from £20 to £300 and 2% from £300 to £4,000. The fee is already built into the price buyers see. A £15 item shows as about £15.15 + postage.
Vinted adds its fee at checkout, on top of your price. It says the fee is usually 3–8% plus £0.30–£0.80; a typical figure is around 5% + 70p. Because of the fixed part, Vinted's fee is relatively high on cheap items: on a £5 item, the buyer pays about 95p extra.
On eBay, business sellers pay a final value fee (usually 9.9–12.9% depending on category), a 30p or 40p order fee and a 0.35% regulatory fee, plus VAT, but their buyers pay no Buyer Protection fee. Vinted's Pro accounts for businesses don't charge sellers either; buyers pay a Pro version of the Buyer Protection fee.
At Vinted's typical rate, eBay's Buyer Protection fee works out lower at every price, for example about 45p vs 95p on a £5 item and £2.30 vs £2.70 on a £40 item. The gap is small in the middle and bigger on cheap items. If your Vinted checkout shows a lower rate, adjust it above.
Vinted is strongest for clothes, shoes, bags, kids' items and homeware. eBay reaches far more buyers for electronics, collectables, car parts, tools and anything niche or valuable, and it has auctions. If fees are close, list where your buyers are.