Glock 19 vs 21 Size Comparison
The Glock 21 is 0.79 in (20 mm) longer, 0.47 in (12 mm) taller and 0.04 in (1 mm) wider than the Glock 19. With an empty magazine it weighs 5.47 oz (155 g) more. It holds 13 rounds in a standard magazine to the 19's 15. Both drawn to scale from Glock's published dimensions.
Glock 19 vs 21 side by side
Glock A
Glock B
Side profile
From behind
- Slide width
- 1 in1.12 in
- Glock 21 is 0.12 in (3 mm) wider
- Overall width, with controls
- 1.34 in1.38 in
- Glock 21 is 0.04 in (1 mm) wider
Tap the drawing to flip between the Glock 19, the Glock 21 and both.
Photos: Glock 17 Gen5 photo by Tony Webster, cut out by LeoPavouk (CC BY 2.0); Glock 43X photo by Kolomaznik (CC BY 4.0); Glock 17 Gen4 photo by Steve Dock, UK Ministry of Defence (OGL v1.0) Contains public sector information licensed under the Open Government Licence v1.0. Cut out and reshaped to each model's published size by GunPartPicker.
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Quick answer
The Glock 21 is 0.79 in (20 mm) longer, 0.47 in (12 mm) taller and 0.04 in (1 mm) wider than the Glock 19. With an empty magazine it weighs 5.47 oz (155 g) more. It holds 13 rounds in a standard magazine to the 19's 15.
- Glock 19: 7.28 in long, 5.04 in tall, 1.34 in wide, 4.02 in barrel. Glock 21: 8.07 in long, 5.51 in tall, 1.38 in wide, 4.61 in barrel.
One square is one inch. Real Glock photos sized to Glock's published dimensions, checked September 27, 2026.
Is the Glock 19 or 21 bigger?
The Glock 21 is the bigger pistol. Against the Glock 19 it is 0.79 in (20 mm) longer, 0.47 in (12 mm) taller and 0.04 in (1 mm) wider.
Glock 19 vs 21 dimensions
| Dimension | Glock 19 | Glock 21 | B vs A |
|---|---|---|---|
| Overall length | 7.28 in185 mm | 8.07 in205 mm | +0.79 in20 mm |
| Slide length | 6.85 in174 mm | 7.52 in191 mm | +0.67 in17 mm |
| Barrel length | 4.02 in102 mm | 4.61 in117 mm | +0.59 in15 mm |
| Height with magazine | 5.04 in128 mm | 5.51 in140 mm | +0.47 in12 mm |
| Overall width, with controls | 1.34 in34 mm | 1.38 in35 mm | +0.04 in1 mm |
| Slide width | 1 in25 mm | 1.12 in28 mm | +0.12 in3 mm |
| Trigger reach | 2.76 in70 mm | 2.85 in72 mm | +0.09 in2 mm |
| Weight, empty magazine | 23.63 oz670 g | 29.1 oz825 g | +5.47 oz155 g |
| Capacity, standard magazine | 15 rounds | 13 rounds | −2 |
| Caliber | 9mm | .45 ACP | Different |
| Glock catalog | Current model | Current model |
Glock 19 vs 21 grip length
The Glock 21 stands 0.47 in (12 mm) taller than the Glock 19 with a magazine in (5.51 in against 5.04 in). Trigger reach, from the back of the grip to the trigger, is 2.85 in on the Glock 21 against 2.76 in on the Glock 19. The two frames are different families (double stack and large frame), so the height gap is overall height, not only grip length.
Glock 19 vs 21 barrel and slide length
The Glock 21 barrel is 0.59 in (15 mm) longer: 4.61 in against 4.02 in. Its slide is 0.67 in (17 mm) longer (7.52 in against 6.85 in).
Will a Glock 21 fit a Glock 19 holster?
Usually not. The Glock 21 is a large frame frame and a Glock 19 holster is molded around a double stack frame, so the fit and retention will be wrong. Holster makers mold for exact models, so check the maker's fit list before you buy.
Is the Glock 21 compact or subcompact?
Glock puts the Glock 21 in its full size large frame class and the Glock 19 in its compact class. Here is every current Glock at the same scale.
Subcompact slimline
Subcompact
Compact
Full size
Every card is to the same scale, lined up at the slide rear. Tap one to compare it or look at it alone.
Where can I buy a Glock 19 or 21 today?
Glock 19 in stock
In stock now. One listing per model family.
Glock 21 in stock
In stock now. One listing per model family.
More Glock 19 and 21 comparisons
Frequently Asked Questions
How much smaller is the Glock 19 than the Glock 21?
0.79 in (20 mm) shorter, 0.47 in (12 mm) lower and 0.04 in (1 mm) narrower, by Glock's published dimensions.
Which is lighter, the Glock 19 or the Glock 21?
The Glock 19, by 5.47 oz (155 g) with an empty magazine: 23.63 oz (670 g) against 29.1 oz (825 g) for the Glock 21.
Which holds more rounds, the Glock 19 or the Glock 21?
The Glock 19: 15 rounds in a standard magazine against 13 for the Glock 21, as Glock's spec pages list them.
Where do these Glock 19 and Glock 21 numbers come from?
From Glock's own US spec pages, checked September 27, 2026. Both guns are shown at one scale, as real Glock photos reshaped to those numbers.
Cite this tool: GunPartPicker, “Glock 19 vs 21 Size Comparison”, https://gunpartpicker.net/tools/glock-size-comparison/glock-19-vs-21. Data from the GunPartPicker catalog and real community builds, prices checked November 11, 2026. Free to cite with attribution.
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