Train from Paris - Avignon - difference between Ouigo and TGV Inoui

Both Ouigo and TGV Inoui are operated by the French national railway operator (SNCF) -- TGV Inoui is a "standard" product whereas Ouigo is a "low-cost" product. (I think their branding/naming scheme in general is kind of wacko, but I'm getting off topic here...)

The travel time is basically the same. Once the TGV Inoui tickets are released, you will probably also notice that the Ouigo trains are much cheaper.

These much cheaper trains come with a number of restrictions:

• Strict luggage requirements of 1 carry-on bag at 55x35x25 cm and 1 hand item at 36x7x15 cm. All other additional luggage has to be paid for ahead of time or at check in, when it will be more expensive. (On normal TGVs the luggage limit is "what you can comfortably carry").
• You must print out your ticket ahead of time or use the smartphone app -- Ouigo tickets cannot be printed at SNCF ticket machines, as normal TGV tickets can
• No cafe car or first class seats
• No seat selection (not even aisle or window), though you can pay more for a seat with power or not
• Check-in starting 30 minutes before the train departs

As you can basically see, Ouigo is applying the "low cost airline" model where the base ticket is cheap but there are lots of restrictions and fees for things that are otherwise free on the "normal" TGVs. It's up to you whether the cost savings are worth it.

Finally, it's worth noting if you don't have a credit card from a finite list of countries that you can't buy Ouigo tickets at all, though as of early 2020 this includes the US, Canada and Australia (among other countries).

If you can book Ouigo now for less than 60-70 euros, it will be cheaper than Inoui.

Differences: Ouigo mimics low-cost airlines in several ways.
- Luggage beyond cabin size requires payment (5 euros IIRC)
- No bar: no food and drinks sold on board
- Print-at-home or mobile tickets only
- Tighter seating arrangement (but the difference between 2nd class TGV inoui and Ouigo is not huge, so Ouigo is still OK for the sub-3 hour ride from Paris to Avignon)
- Need to be at the station at least 30 minutes before departure for check-in (not an issue for most tourists)
- Tickets are non-refundable

Personally, I need flexibility, I like sipping a coffee at 300 kph, I have a discount card for regular (Inoui) TGV, and I get to the station at the last minute: I let you guess my opinion of Ouigo. But for very occasional trips, it is worth a shot.

(I think their branding/naming scheme in general is kind of wacko, but I'm getting off topic here...)

Try extremely wacko (in my humble opinion)

Thank you all for your detailed answers! This really helps! :)