A small hole does not automatically end a sock's useful life. The condition around the damage matters. If enough sound fabric remains, a darn may be worthwhile. When a broad area is extremely thin or the cuff no longer works, another decision may make more sense.
Assess more than the visible hole
Wash the sock according to its care instructions and let it dry. Examine the matching sock as well as the toe, heel, and sole. This helps distinguish one localized hole from general wear. Do not immediately cut away a wide area of fraying, because that can unnecessarily enlarge the gap needing repair.
Choose yarn whose thickness and care requirements suit the sock. Very bulky thread can create an uncomfortable hard spot. A contrasting color may make new strands easier to see during a first attempt. If you want a less visible result later, use a closer match without making a valuable pair your first practice project.
Bridge a small gap
Place the damaged area over a suitable smooth darning support without overstretching it. Secure the sound surrounding fabric, then lay parallel strands across the opening. Weave across them, alternating over and under, and secure the ends flat. The iFixit guide illustrates this basic method on a sock with a small hole.
Keep tension gentle and consistent. Pulling the repair tight can leave puckering when the support is removed and create pressure during wear. Check the reverse while working so you do not accidentally sew both sides of the sock together. A suitable firm support also helps keep the needle away from your fingers.
For practice, choose a small accessible area rather than a large opening on a heavily worn heel. The largest needle available is not automatically appropriate; it needs to suit the thread and fabric. Stop if surrounding stitches continue to break or the material cannot hold the repair securely.
Judge the result by comfort
Remove the support and inspect the repaired area flat on a table. Then try the sock briefly. A repair beneath the foot needs to feel comfortable: a thick knot or stiff ridge is particularly noticeable there. Adjust loose ends if needed without undoing their anchoring.
Continue washing according to the sock's care instructions and check the repair after subsequent use. A visible patch is not inherently a failed repair. Secure attachment and a wearable fit matter more than making every new thread disappear. Keep suitable leftover yarn identified if the partner sock may need attention later. That makes the next small repair easier to begin without another search for matching supplies.
