Dating guitar effects; how old is your pedal?

Would you like to know when a guitar effect has been produced? Try one of the following websites. They offer decoders that allow you to look up the age of your guitar effect.

Boss

At Boss pedals you can find the serial number at different locations: The oldest versions have these numbers printed in the battery compartment, just above the switch. Later, a sticker was used, which can also be found in the battery compartment. The latest pedals have a serial number printed on the back of the label. You can enter it at the following websites to decipher the production date:
Boss pedal production date link #1
Boss pedal production date link #2

Ibanez

Ibanez does not use serial numbers to decode. At the following website you can look up the production data of a certain type of pedal to get an overall impression of how old the effect is.
Ibanez pedal production date link #1

Electro-Harmonix (EHX)

EHX has not provided serial numbers on their products. There are several pages specialized however on various popular EHX effect pedals which can provide information on the age of your EHX pedal.
EHX Big Muff versions link #1
EHX Electric Mistress versions link #1

DOD

Also DOD does not give a precise production date of an effect. You can look up when and how long a specific pedal was made.
DOD pedal production date link #1
It is probably more accurate to look up the code on the back of the potentiometer (rotary knob) via a potentiometer decoder; see below.

Potentiometer codes

Often a code is printed on the back of the older potentiometers. You will not only find these pots in guitar effects, but also in guitars. On the basis of this code you can derive the manufacturer and production date of the pot. That is an indication of how old the instrument is!
Potentiometer code production date link #1
Potentiometer code production date link #2

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