(as|) good as new

used of something that was not working or functioning well, but it is now in good condition

The idiom "good as new" originated in the late 19th century and is used to describe something that has been restored or repaired to its original condition, resembling a state of being brand new. The phrase suggests that the item or object in question is in excellent or pristine condition, as if it had never been used or experienced any wear or damage. It implies a successful restoration or refurbishment, resulting in a product that is indistinguishable from its original state.

After the thorough cleaning, the antique clock looked as good as new, with its intricate details shining brightly.
The mechanic fixed the car's engine, and now it runs smoothly and is good as new.
Despite the accident, the laptop was repaired and now functions perfectly, appearing as good as new.
The tailor mended the torn dress, and with its flawless stitching, it looked good as new.
The dentist restored the chipped tooth with a filling, leaving it looking and feeling as good as new.

(of a person physically ill) restored back to full health or regained full function of one's body

In a day or so he will be as good as new.
Send him on a vacation to Hawaii and he'll be good as new.

not new, but in such great condition that looks or feels like new

His shoes are old but still as good as new.
The car may be a few years old, but it's as good as new.
She kept her phone in such great condition, it was as good as new.
"His camera is old, but it works good as new.
The rug still feels as good as new after all these years.