First, prove it. Plug a laptop into the router with a network cable and run a speed test. If the wired speed is close to what you pay for, your line is fine — the problem is WiFi, and the fixes below cost nothing.
1. Move the router
WiFi hates walls, floors, water (including people) and metal. A router in a cupboard by the front door will never cover a home well. Put it central, elevated and out in the open — not behind the TV, not in a media cabinet.
Biggest single win: raising the router off the floor and into the open often does more than any setting change. Signal radiates outward and downward.
2. Use the right band
Modern routers broadcast two networks: 2.4GHz (slower, but travels far and through walls) and 5GHz (much faster, but shorter range). Connect nearby devices to 5GHz for speed; leave distant devices and smart-home gear on 2.4GHz.
3. Beat interference
In flats and complexes, dozens of WiFi networks fight over the same channels. Many routers auto-pick a clear channel on reboot — so a simple restart can help. If yours lets you, set a fixed, less-crowded channel.
4. Check the crowd
Every connected device shares the airtime. A house full of phones, TVs, cameras and a downloading console will feel slow even on a big line. Pause big downloads, and wire up the things that sit still — TV, desktop, console — with Ethernet.
5. When to upgrade hardware
If you’ve done all the above and large rooms still drop, the free ISP router may simply be underpowered for your home. A mesh WiFi system blankets bigger or double-storey homes far better than a single router. Upgrade hardware before paying for a faster line — speed you can’t receive is wasted money.