A gate that sags, drags on the ground, or will not latch is usually caused by loose hardware, a racked frame, or a leaning post. Most sagging gates can be fixed in under an hour with basic tools and inexpensive hardware.

How to Fix a Sagging Gate

Diagnose the Problem

Stand back and look at the gate from the latch side:

Gate frame is racked (parallelogram shape): The gate has shifted out of square, dropping the latch side downward
Hinges are loose or pulling out: The screws have stripped in the post or the gate rail
Post is leaning: The hinge post tilts away from the gate, causing the gate to drag
Gate boards are rotted: Structural boards have weakened and can no longer hold square

Fix 1: Anti-Sag Kit (Turnbuckle and Cable)

This is the most effective and universal fix for a racked gate.

Purchase a gate anti-sag kit (available at any hardware store for $10 to $20) — it includes a steel cable, a turnbuckle, and corner brackets
Install the corner brackets diagonally — one at the top hinge corner and one at the bottom latch corner
Run the cable between the brackets through the turnbuckle
Tighten the turnbuckle to pull the latch side of the gate upward until the gate is square and the latch engages
Check by opening and closing the gate — adjust as needed

The cable creates a diagonal brace that counteracts the sagging force. This works on wood fence gates of any size.

Fix 2: Tighten or Replace Hinges

Loose hinge screws are the simplest cause and fix:

Tighten all hinge screws with a screwdriver or drill
If screws spin (stripped holes), replace them with longer, thicker screws
For severely stripped holes, fill the holes with wooden dowels or golf tees coated in wood glue, let dry, then redrive the screws
If the hinges themselves are bent or worn, replace them with heavy-duty T-hinges or strap hinges rated for the gate weight

Fix 3: Add a Diagonal Brace

A permanent structural fix:

Cut a 2x4 or 1x6 board to span diagonally from the upper hinge corner to the lower latch corner of the gate frame
The brace should run from high (hinge side) to low (latch side) — this is critical. A brace running the wrong direction makes sagging worse.
Screw the brace to every horizontal rail and the vertical frame members
This converts the gate from a weak rectangle to a rigid triangle

Fix 4: Straighten a Leaning Post

If the hinge post leans:

Check if the post base is rotted — if so, replace the post
If the post is solid but leaning, brace it with a diagonal support stake driven into the ground and screwed to the post
For a permanent fix, dig alongside the post base and add concrete to stabilize it
Let concrete cure for 48 hours before hanging the gate back on

Upgrading the Latch

A gate that swings and latches smoothly should have:

Self-closing spring hinges or a gate spring that pulls the gate closed
An adjustable latch that allows fine-tuning the catch point
A cane bolt or drop rod for double gates to lock the stationary panel

Prevention

Use heavy-duty hardware rated for the gate weight and size
Build gate frames with diagonal braces during construction
Set gate posts in concrete with at least 2 feet of depth
Apply wood preservative to all ground-contact post sections
Periodically tighten hinge screws and check latch alignment
Keep the gate area clear of debris and vegetation that can obstruct movement

A properly repaired and reinforced gate operates smoothly for years. Address sagging at the first sign rather than waiting for the problem to worsen.