
instant
Describes foods or products that are instantly soluble or ready to use, usually by simply adding water or another liquid.
Wenn es schnell gehen muss, trinke ich einen Instantkaffee.
When things have to be quick, I drink instant coffee.
Loading your saved state.

Describes foods or products that are instantly soluble or ready to use, usually by simply adding water or another liquid.
Wenn es schnell gehen muss, trinke ich einen Instantkaffee.
When things have to be quick, I drink instant coffee.

Refers to something that happens immediately or instantly. This meaning is borrowed from English and is often used in technical or digital contexts.
Die neue App bietet eine Instant-Übersetzung von fremdsprachigen Texten.
The new app offers instant translation of foreign-language texts.
'Instant' is a loanword from English and is almost always used in German as the first part of a compound noun (e.g., 'Instant-Kaffee' (instant coffee)). In this function, it is not declined and is often written with a hyphen.
Für die Reise habe ich mir eine Packung Instant-Nudeln gekauft.
For the trip, I bought myself a pack of instant noodles.
In the food sector, 'instant' refers to products that can be prepared quickly with liquid. Common examples are 'Instantkaffee' (instant coffee), 'Instantsuppe' (instant soup), 'Instantbrühe' (instant broth), or 'Instantpüree' (instant mashed potatoes).
Morgens trinke ich nur einen schnellen Instantkaffee.
In the morning, I only drink a quick instant coffee.
The meaning 'sofortig' (immediate) is used especially in the digital and technical field. Typical terms are 'Instant-Messaging' (as with WhatsApp), 'Instant-Zugriff' (instant access), or 'Instant-Feedback' (instant feedback).
Die App bietet Instant-Messaging mit allen Kontakten.
The app offers instant messaging with all contacts.
immediate / direct
Unmittelbar and instant can mean that something happens without delay. Unmittelbar is more general and sounds rather formal. Instant is borrowed from English and is used especially in technical or digital contexts.

Die neue App bestätigt den digitalen Auftrag instant.
The new app instantly confirms the digital order.
Nach dem Klick erhält die Kundin unmittelbar eine Bestätigung.
After clicking, the customer receives an immediate confirmation.