Is the M3 worth stepping up to from the M2?

Yes if you keep laptops a long time, use two monitors, or want Wi-Fi 6E and ray tracing. If you mostly write, browse and stream, the M2 handles it and the gap is small.

Which is better for video editing?

The M3. It has a faster GPU, hardware ray tracing and the same ProRes media engine, so exports and effects render quicker. Both need 16 GB of memory for serious editing.

Do they have the same screen and battery?

Yes. Both use a 13.6-inch 2560x1664 Liquid Retina panel at 500 nits and are rated up to 18 hours of video playback.

The M3 should stay useful longer because of its newer chip and wireless. Both are fanless with sealed batteries, so real lifespan depends on charge cycles and memory chosen at purchase.

Can I use two monitors with either?

Only the M3 runs two external displays, and only with the lid closed. The M2 supports a single external display.

Is 8 GB of memory enough?

For email, web and documents, yes. For photo editing, coding with containers or many tabs, get 16 GB on either model; memory cannot be upgraded later.

Apple MacBook Air M3 vs Apple MacBook Air M2 13.6-inch

Both are 13-inch MacBook Airs with the same 2560x1664 Liquid Retina display, 18-hour battery rating, MagSafe charging and fanless design. The M3 adds a faster chip with hardware ray tracing, Wi-Fi 6E, Bluetooth 5.3 and support for two external displays with the lid closed; the M2 is the older chip and tops out at one external display. Buyers who mostly browse, write and stream will not feel much difference day to day, but the M3 is the better long-term pick and the one reviewers recommend for anyone keeping a laptop four years or more.

Choose the MacBook Air M3 if you want the newer chip, Wi-Fi 6E, dual external display support, or plan to keep the laptop for years.
Choose the MacBook Air M2 if you want the same screen and battery in a proven design and the M2 chip already covers everything you do.

Prices

Apple MacBook Air M3: $629.30 at CTT Home & Culinary (last seen Nov 3)