SIHOO B100 Pro vs FlexiSpot OC3: Which Should You Buy?

Key difference: The B100 Pro has 4D armrests where the OC3 has 2D, but the OC3 carries a 5-year warranty.

SIHOO and FlexiSpot each publish their own specifications, and this comparison of the B100 Pro and OC3 uses only those, plus regular US list prices.

Why compare them

Why put the SIHOO B100 Pro next to the FlexiSpot OC3? The SIHOO B100 Pro and the FlexiSpot OC3 are mesh chairs with a headrest at nearby list prices.

Specs side by side

Strengths and weaknesses

SIHOO B100 Pro

Strengths

• 4D armrests, against 2D armrests on the OC3.
• Higher maximum load: 330 lb (≈150 kg), against 300 lb (≈136 kg) on the OC3.
• Deeper recline: up to 135° against 130° on the OC3.
• Lower list price: from $259.99 against $269.99 for the OC3.
• 3D headrest, against 2D on the OC3.
• A Footrest Version is sold; none is listed for the OC3.

Weaknesses

• Shorter warranty: 3 years, against 5 years on the OC3.
• No seat-type choice is listed for the B100 Pro, unlike the OC3.

FlexiSpot OC3

Strengths

• Longer warranty: 5 years, against 3 years on the B100 Pro.
• Choice of a foam or a mesh seat, which the B100 Pro's store listing does not offer.

Weaknesses

• 2D armrests, against 4D on the B100 Pro.
• Lower maximum load: 300 lb (≈136 kg), against 330 lb (≈150 kg) on the B100 Pro.
• Shallower recline: up to 130° against 135° on the B100 Pro.
• Costs more: from $269.99 against $259.99 for the B100 Pro.
• 2D headrest, against 3D on the B100 Pro.
• No footrest version is listed for the OC3, unlike the B100 Pro.

How they differ

Armrests. The SIHOO B100 Pro lists “Enlarged 4D flip-up armrests”, the FlexiSpot OC3 “2D; 3.9" height adjustment”. With 4D armrests the B100 Pro lets you set the pads in more ways than the OC3.

Warranty. The SIHOO B100 Pro lists “3 years”, the FlexiSpot OC3 “5 years”. The OC3's cover runs longer.

Maximum load. The SIHOO B100 Pro lists “330 lb (≈150 kg)”, the FlexiSpot OC3 “300 lb (≈136 kg)”. The B100 Pro is rated for more weight.

Recline. The SIHOO B100 Pro lists “Up to 135°; 3 lock positions”, the FlexiSpot OC3 “90°–130°”. The B100 Pro leans back further.

Price. At regular US list prices the SIHOO B100 Pro is $259.99–$299.99 and the FlexiSpot OC3 is $269.99. The B100 Pro lists $10 below the OC3, before any store sale. Price options: the B100 Pro — Standard Version $259.99, Footrest Version $299.99 (Black and White); the OC3 — OC3, Black or Grey, foam or mesh seat (all four SKUs list at $269.99).

Headrest. The SIHOO B100 Pro lists “Wide 3D adjustable headrest”, the FlexiSpot OC3 “2D headrest; 2.1" height and 30° rotation”. The B100 Pro's headrest has more adjustment than the OC3's.

Seat options. The OC3 is sold with a foam or a mesh seat; the B100 Pro's store listing has no seat-type choice.

Footrest. SIHOO sells a Footrest Version of the B100 Pro; no such version is listed for the OC3.

Seat size. Seat height: the SIHOO B100 Pro lists nothing, the FlexiSpot OC3 “18.5–22.4 in (≈47–57 cm)”. Seat width: the SIHOO B100 Pro lists nothing, the FlexiSpot OC3 “20.4 in (≈52 cm)”. Seat depth: the SIHOO B100 Pro lists nothing, the FlexiSpot OC3 “15.9 in (≈40 cm)”.

Other details. Lumbar support: the SIHOO B100 Pro lists “Responsive lower-back support”, the FlexiSpot OC3 “1.9" Height Adjustable”. Chair weight: the SIHOO B100 Pro lists “36.4 lb (≈16.5 kg)”, the FlexiSpot OC3 “28.66 lb (≈13 kg)”.

Who should buy which

• Pick the B100 Pro over the OC3 if you want 4D armrests rather than 2D.
• Pick the B100 Pro over the OC3 if you want a higher weight rating: 330 lb (≈150 kg).
• Pick the B100 Pro over the OC3 if you want a deeper recline (up to 135°).
• Pick the OC3 over the B100 Pro if you want a longer warranty (5 years).
• Pick the OC3 over the B100 Pro if you want the choice of a foam or a mesh seat.
• Pick the OC3 over the B100 Pro if you want a lighter chair to move around: 28.66 lb (≈13 kg) against 36.4 lb (≈16.5 kg).

Not published by the brand (B100 Pro vs OC3): seat height, seat depth and seat width for the SIHOO B100 Pro.

Sources

• SIHOO B100 Pro (compared here with the OC3): Sihoo B100 Pro Ergonomic Office Chair With Flip-Up Armrest – Official US Sihoo Store, checked 2026-10-09; US list price from SIHOO US Official Store, checked 2026-10-09.
• FlexiSpot OC3 (compared here with the B100 Pro): Essential Office chair (OC3) - FlexiSpot official store (SPEC tab), checked 2026-09-29; US list price from FlexiSpot US Store (flexispot.com), checked 2026-09-29.
• Figures marked ≈ for the B100 Pro and OC3 are Chairpedia's unit conversions, not brand figures.