The short version
Textra is a good app. It has been around for over a decade, holds roughly a 4.0 average from more than 440,000 ratings, and is more polished in places than Lounge is today.
The difference is what each one is built around. Textra is a highly customizable texting app funded by advertising, with a purchase to remove the ads. Lounge is built so that it cannot phone home at all, and sells a one-time unlock for its extras.
What Textra does well
Credit where it is due. Textra’s customization is deep and has been refined over years. Its per-contact settings, bubble styles and notification controls are thorough. It supports scheduled messages and a long tail of small conveniences that only turn up after a decade of real use.
It also has something Lounge does not and cannot buy: hundreds of thousands of people who have used it for years, and the stability that comes from that much exposure.
Where the two genuinely differ
Advertising. Textra’s Play listing states that it contains ads and offers in-app purchases. Lounge has no ads at any tier, and no advertising or analytics SDK in the package.
Network access. Lounge does not declare the internet permission, so Android will not let it open a connection. You can verify that on the Play listing before installing. What that means in practice.
A private vault. Lounge can encrypt a conversation behind a passcode of its own and lift it out of Android’s message database entirely, so other SMS apps stop seeing it. Textra has no equivalent.
Messages that delete themselves. Lounge can expire a conversation’s messages on a schedule you set, from five minutes to a month. Textra does not do this.
Shape of the purchase. Both are $9.99. With Textra you are buying the removal of advertising. With Lounge you are buying features — auto-reply, five more send buttons, repeating schedules and the vault — on an app that had no advertising to remove.
Where Textra wins
Maturity, mostly, and that is not a small thing. Ten years of edge cases have been found and fixed in Textra that Lounge has not met yet. If you want the safest, most-tested third-party SMS app on Android, that is a reasonable thing to optimize for and Textra is the better pick.
It also has far more people using it, which means more help available when something goes wrong.
Which one should you install?
Pick Textra if you want years of polish and deep per-contact customization, and you are comfortable with an ad-funded app that you can pay to quiet.
Pick Lounge if the thing you actually want is a texting app that structurally cannot send anything anywhere — and you would use an encrypted vault, filters you write yourself, or messages that clean themselves up.
They are both free to try, and switching your default SMS app takes about ten seconds either way.
The full picture
The homepage carries a complete row-by-row comparison of Lounge against Textra and Pulse SMS — including the rows Lounge loses, with its sources and the dates they were checked.
Try it
Lounge is on Google Play. Free, with a one-time unlock for the extras — no subscription, no account, nothing to cancel.