Net Income (Loss) per Share - Computation of Net Income (Loss) per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Denominator:
Basic weighted-average common shares outstanding (in shares)	182,024,207	70,240,492
Basic income (loss) per share attributable to common stockholders	$ 0.14	$ (8.19)
Denominator:
Basic weighted-average common shares outstanding (in shares)	182,024,207	70,240,492
Shares used in computation of diluted net income (loss) per share attributable to common stockholders	201,275,223	70,240,492
Diluted income (loss) per share attributable to common stockholders (in dollars per share)	$ 0.13	$ (8.19)
Class A
Numerator:
Net income (loss) attributable to common stockholders	$ 18,214	$ (92,094)
Denominator:
Basic weighted-average common shares outstanding (in shares)	126,746,933	11,248,688
Basic income (loss) per share attributable to common stockholders	$ 0.14	$ (8.19)
Numerator:
Net income (loss) attributable to common stockholders	$ 18,974	$ (92,094)
Denominator:
Basic weighted-average common shares outstanding (in shares)	126,746,933	11,248,688
Weighted average effect of dilutive potential common stock (in shares)	19,251,016	0
Shares used in computation of diluted net income (loss) per share attributable to common stockholders	145,997,949	11,248,688
Diluted income (loss) per share attributable to common stockholders (in dollars per share)	$ 0.13	$ (8.19)
Class B
Numerator:
Net income (loss) attributable to common stockholders	$ 7,944	$ (482,972)
Denominator:
Basic weighted-average common shares outstanding (in shares)	55,277,274	58,991,804
Basic income (loss) per share attributable to common stockholders	$ 0.14	$ (8.19)
Numerator:
Net income (loss) attributable to common stockholders	$ 7,184	$ (482,972)
Denominator:
Basic weighted-average common shares outstanding (in shares)	55,277,274	58,991,804
Weighted average effect of dilutive potential common stock (in shares)	0	0
Shares used in computation of diluted net income (loss) per share attributable to common stockholders	55,277,274	58,991,804
Diluted income (loss) per share attributable to common stockholders (in dollars per share)	$ 0.13	$ (8.19)

Reddit, Inc. 10-Q