The Betamax is Sony's 12.7 mm, 0.5 inch home video cassette tape recording format. Sony introduced the Betamax in 1975, inspired from the earlier professional 19.1 mm, 0.75 inch U-matic video cassette format. The Betamax has no guard band and uses azimuth recording to reduce cross-talks. The word 'Betamax' was coined because when the tape ran, it looked like the Greek letter 'beta'.

The gadget offers functions such as peek search, HiFi videos, automatic program search, tape remaining counters etc. It also offers better resolution since it uses more tape for each second as compared to other formats. Betamax is equipped with features such as PCM mode (Pulse Code Modulation), tracking control (tracking normal/tracking slow), go to zero (which allows the tape to go to the point where the counter read zero), speed controls, TV Vert Lock (removes the jitters that is experienced when the picture is either paused or in slow motion), tape changers, linear stereo, fluorescent display dimmer etc. Betamax videos such as SL-8000, SL-8080, SL-C7, SL-C20, SL-HF150, SL-HF100, SLO-1700 are available over the internet. One can come across Betamax video recorders manufactured by Sony, Sanyo, Toshiba, Pioneer, NEC, and Aiwa. Betamax tapes by Sony, such as the L-125, L-165, L-500, L-830, L-750 etc., come in different lengths and sizes.

The world's first camcorders were of the Betamax format and labeled the 'Betamovie'. BetaCam is now de-facto in professional TV companies. Since Betamax tapes became difficult to obtain, Sony started offering BataCam tapes, which use cassettes that are compatible with Betamax recorders. Sony also offers Beyond Ferric tapes, cleaning tapes, service tapes, tape re-winders etc.