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A man uses his mobile phone in front of a giant advertisement promoting Samsung Electronics' new Galaxy S5 smartphone at an art hall in central Seoul April 15, 2014. Reuters

With the Samsung Galaxy S6 set to release Friday, now is the perfect time to trade in your old Samsung Galaxy smartphone to get the best price before purchasing the new model.

The 2015 flagship is selling for $199 with a two-year contract with most carriers and for at least $650 with no contract, which is quite pricey. But by trading in your old Galaxy model, you can get up to $300 to put toward a new device. Trading companies, including Gazelle, Nextworth and Glyde, are offering nice sums for Galaxy S5, Galaxy S4 and Galaxy S3 models.

Here’s a rundown of which Samsung Galaxy models have the best trade in value based on carrier and color.

Values are dependent on color of the device in addition to whose network it runs on. Across the board, AT&T devices have the highest trade in value, followed by T-Mobile devices, then Verizon and finally Sprint. Among the three websites, Glyde has the highest trade in values for the Galaxy S5, Galaxy S4 and Galaxy S3.

Keep in mind that price estimates are subject to change and could be higher or lower than the listed prices.

Gazelle

The website has a simple user interface and an extremely easy questionnaire to determine the value of a smartphone; one to two questions will give you an estimate. Gazelle doesn’t take into consideration the color of the handset, but you may need to know the model number to select your device. The best trade in value is for AT&T and Verizon models.

Samsung Galaxy S3 16GB: AT&T: $65
Samsung Galaxy S3 16GB: Sprint: $20
Samsung Galaxy S3 16GB: T-Mobile: $65
Samsung Galaxy S3 32GB: Verizon: $50

Samsung Galaxy S4 16GB: AT&T: $110
Samsung Galaxy S4 16GB: Sprint: $80
Samsung Galaxy S4 16GB: T-Mobile: $120
Samsung Galaxy S4 16GB: Verizon: $110

Samsung Galaxy S5 16GB: AT&T: $210
Samsung Galaxy S5 16GB: Sprint: $170
Samsung Galaxy S5 16GB: T-Mobile: $195
Samsung Galaxy S5 16GB: Verizon: $210

Nextworth

The website has a slightly challenging user interface and an easy questionnaire to determine the value of a smartphone, containing six questions. Nextworth takes into consideration the color of the handset, but all of the colors yield the same price. The best trade in value is for AT&T and T-Mobile models.

Samsung Galaxy S3 16GB: White/Red/Blue -- AT&T: $42
Samsung Galaxy S3 16GB: White/Blue/Purple -- Sprint: $16
Samsung Galaxy S3 16GB: White/Blue -- T-Mobile: $42
Samsung Galaxy S3 16GB: Black/White/Blue/Brown -- Verizon: $28

Samsung Galaxy S4 16GB: Black/White/Red/Blue -- AT&T: $73
Samsung Galaxy S4 16GB: Black/White/Blue/Purple -- Sprint: $62
Samsung Galaxy S4 16GB: Black/White -- T-Mobile: $91
Samsung Galaxy S4 16GB: Black/White/Blue/Brown -- Verizon: $74

Samsung Galaxy S5 16GB: Black/White/Gold -- AT&T: $150
Samsung Galaxy S5 16GB: Black/White/Gold -- Sprint: $95
Samsung Galaxy S5 16GB: Black/White/Gold -- T-Mobile: $159
Samsung Galaxy S5 16GB: Black/White/Gold -- Verizon: $122

Glyde

The website has a simple user interface and an easy questionnaire to determine the value of a smartphone, containing four questions. Glyde takes into consideration the color of the handset, which may affect its price, as will the carrier model. The best trade in value is for AT&T and T-Mobile models.

Samsung Galaxy S3 16GB: Blue -- AT&T: $122
Samsung Galaxy S3 16GB: Blue -- Sprint: $29
Samsung Galaxy S3 16GB: Blue -- T-Mobile: $139
Samsung Galaxy S3 16GB: Brown -- Verizon: $136

Samsung Galaxy S4 16GB: White -- AT&T: $175
Samsung Galaxy S4 16GB: Black/White/Blue/Purple -- Sprint: $78
Samsung Galaxy S4 16GB: Black/White -- T-Mobile: $182
Samsung Galaxy S4 16GB: Blue/Brown -- Verizon: $170

Samsung Galaxy S5 16GB: White -- AT&T: $299
Samsung Galaxy S5 16GB: Black/White -- Sprint: $146
Samsung Galaxy S5 16GB: White -- T-Mobile: $323
Samsung Galaxy S5 16GB: Black -- Verizon: $312