A guide to all those who are planning to buy a Rolex. This guide details how to spot a fake Rolex, all methods are gathered from online sources and pawnshop owners.
(1) Price of the watch
If the price of the Rolex offered is too low to beleive, it probably is fake.
(2) Caseback
Rolex does not make watches with display caseback or engraved caseback. (exception is Sea Dweller model with engraved with "ROLEX OYSTER ORIGINAL GAS ESCAPE VALVE" on the caseback).

Fake with clear caseback.

Fake with engravings.
(3) Weight
A real Rolex will feel heavy and solid in your hand. When you move the bracelet aroung it will not make any noise but flex smoothly according to the movement of the hand.
(4) Dial Printing
Some lower grade fakes will have errors in printing on the dial, such as misspelled words. The printing on a real Rolex will be crisp and clear. If examined through a loupe it will not have excess ink on the side, it will be flush with the dial.

(5) Hands
The watch hands will be thick and not thin. The lume on the hands will also be evenly applied. The second hand will extend onto the seconds marker. Fakes usually have thin hands and short second hands.

Fake with short hands.

Fake with thin hands.
(6) Hologram sticker on case back
All original Rolex comes with a green hologram with the word ROLEX repeated on the design, when viewed from different angles. A hologram crown is also printed in the middle of the sticker. The serial number of the watch is printed in black ink below the holographic crown. Fakes usually have non holographic labels.

(7) Engraved serial number.
All new Rolex have serial numbers engraved between the lugs at the 6 o'clock position. Real Rolex engraving is clean and crisp, fakes usually have etched numbers. At the 12 0'clock position between the lugs will be engraved Original Rolex Design. The serial number is also engraved on the chapter ring at the 6 o'clock position.


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Engraving on the Clasp
Real Rolex clasps are solid and the Rolex word is engraved onto the folding parts and not stamped or etched as in fakes.

(9) Cyclops Date magnifier
Real Rolex cyclops magnifier will magnify the date by 2.5x and the date will seem to fill up the lens. Fake Rolex lenses are usually not magnifying at all.

(10) Rolex triplock crown
Real Rolex such as Submariner, Sea Dweller and Daytona features the triplock crown. On real Rolex there will be a visible rubber seal when the crown is unscrewed.

(11) Laser Engraved Crown (LEC)
New Rolex features a micro laser engraved crown (LEC) at the 6 o'clock position on the crystal. This will be visible under a loupe. On real Rolex the LEC is very crisp. On fakes, the LEC is actually etched and are usally blurred and the balls dimensions are smaller. Rolex with replaced crystal during servicing has a s in the bottom of the LEC.

Real LEC

Fake LEC

Original replaced crystal with LEC
(12) Inside movement.
The best way to tell is actually to have a watchmaker open the caseback to see the movement inside.
This is just a basic guide and to all others out there feel free to contribute if you have other info. Hope this helps.

Note: All photos credit goes to the respective websites.