Upgrade Guide

Sony A6400→Sony Sony A9 III

Is it worth upgrading? Spec analysis, key improvements, and our verdict.

You own

Sony

A6400

£899

2019

→

Upgrade to

Sony

Sony A9 III

£5999 (+£5,100)

2023

✅

Worthwhile

Clear improvements over the A6400. Whether it justifies the cost depends on which upgrades matter most to your shooting.

What's new in the Sony A9 III

↑

Weather sealing

Added — fully sealed body
↑

Burst rate

120fps blackout-free electronic vs 11fps mechanical, 8fps with AF tracking
↑

Battery life

530 shots (CIPA) vs ~410 shots (CIPA)
↑

Generation

4 years newer (2023 vs 2019)

Unchanged or similar

Suitability by genre

Full spec comparison

Spec	A6400	Sony A9 III
Price	£899	£5,999
Released	2019	2023	↑
Sensor	24.2MP APS-C Exmor CMOS BSI	24.6MP full-frame Exmor RS CMOS (global shutter)
Resolution	24MP	25MP	↑
Video	4K/30p (6K oversampled, no crop), 1080p/120p slow-motion	4K/120p, 4K/60p, 1080p/240p
Autofocus	Phase-detect, 425 points, real-time Eye AF & animal AF	AI subject recognition AF, 759-point phase-detect
Stabilisation	None (no IBIS)	8-stop IBIS
Burst Rate	11fps mechanical, 8fps with AF tracking	120fps blackout-free electronic	↑
Battery Life	~410 shots (CIPA)	530 shots (CIPA)	↑
Weight	403g (body, battery, card)	703g body only	↓
Weather Sealed	No	Yes	↑
Viewfinder	EVF, 2.36M dots, 0.70× magnification	0.64" Quad-XGA OLED EVF, 9.44M dots
Screen	3.0" tilting touchscreen, 180° flip for selfie/vlog, 921k dots	3.2" fully articulating touchscreen
Mount	Sony E-mount	Sony FE (E-mount)
Memory Cards	Single SD UHS-I	Dual CFexpress Type A / SD UHS-II

Compare side-by-side

See A6400 and Sony A9 III next to each other with our interactive comparison tool.

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Other upgrades from the A6400

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