Перед заказом лучше проверить наличие товара в приложении.

Because the preposition перед normally takes the instrumental case when it means before in time or in front of in space.

So:

• заказ = order
• перед заказом = before the order / before ordering

The instrumental singular ending here is -ом, which is a common masculine ending:

• заказ → заказом
• стол → столом
• магазин → магазином

So the phrase literally means before the order or more naturally before ordering.

Here лучше means it is better to or you’d better.

In this sentence, Russian uses an impersonal structure:

• лучше проверить = it is better to check

There is no explicit subject like you or we. Russian often leaves that unstated when giving general advice.

So the sentence is not literally Before the order, better checks... but rather:

• Перед заказом лучше проверить... = Before ordering, it’s better to check...

Also note that лучше is the comparative form related to хорошо:

• хорошо = well / good
• лучше = better

Because after лучше in this kind of advice structure, Russian often uses the infinitive.

Pattern:

• лучше + infinitive

Examples:

• Лучше подождать. = It’s better to wait.
• Лучше позвонить заранее. = It’s better to call in advance.
• Перед заказом лучше проверить наличие товара. = Before ordering, it’s better to check whether the item is available.

This is a very common way to give recommendations in Russian.

Because проверить is the perfective form, which presents the action as a single complete check.

• проверять = imperfective, to be checking / to check in general
• проверить = perfective, to check and complete the check

In this sentence, the idea is:

• before ordering, do one complete check of the item’s availability

So проверить is the natural choice.

If you used проверять, it would sound more like a general process or repeated action, which is less suitable here.

Наличие товара means the availability of the product/item or whether the item is in stock.

Breakdown:

• наличие = presence, availability, stock status
• товар = product, item, goods

In shopping language, наличие товара is very common and refers to whether something is available for purchase.

A very natural English equivalent is:

• check if the item is in stock
• check the item’s availability

Because наличие requires the thing that is available to be in the genitive case.

So:

• товар = item, product
• товара = of the item / item’s

This is a common noun + genitive pattern in Russian, similar to:

• цена товара = the price of the item
• описание товара = the description of the item
• наличие товара = the availability of the item

So literally, наличие товара is the availability of the item.

Because after в meaning in, Russian often uses the prepositional case when talking about location.

So:

• приложение = app / application
• в приложении = in the app

The ending -ии is normal here because приложение is a neuter noun ending in -ие.

Compare:

• в магазине = in the store
• в приложении = in the app
• в сообщении = in the message

In this sentence, в приложении tells you where to check the availability.

Yes, by itself в приложении can also mean in the appendix or in the attachment, depending on context.

But in this sentence, because we are talking about ordering and checking product availability, the meaning is clearly:

• in the app

So context is what tells you which meaning is intended.

Yes, in a practical sense there is an implied you, but Russian does not need to state it.

The sentence gives general advice:

• Перед заказом лучше проверить... = Before ordering, it’s better to check...

In English, we might naturally say:

• Before ordering, you should check...
• Before placing an order, it’s better to check...

Russian often prefers this more impersonal style in instructions, advice, notices, and customer-facing text.

Yes, in translation it often works best as before ordering, even though the Russian noun is literally before the order.

Russian often uses a noun phrase where English might prefer a gerund:

• Перед заказом = before the order = before ordering

So a natural English translation is not always word-for-word. In context, before ordering sounds more idiomatic.

Yes. Russian word order is flexible, though some versions sound more natural than others.

Original:

• Перед заказом лучше проверить наличие товара в приложении.

This is neutral and natural.

Possible variations:

• Лучше перед заказом проверить наличие товара в приложении.
• Наличие товара лучше проверить в приложении перед заказом.

These are understandable, but they shift emphasis slightly.

The original version is good because it starts with the time frame before ordering, then gives the recommendation, then the action.

Yes, до заказа is possible and would also mean before the order / before ordering.

But there is a small difference in feel:

• перед заказом = before ordering, right before that action
• до заказа = before the order, more generally prior to it

In this kind of customer instruction, перед заказом sounds very natural because it suggests something you should do immediately before placing the order.

So:

• Перед заказом лучше проверить... feels very idiomatic here.

A helpful stress guide is:

• Перед зака́зом лу́чше прове́рить нали́чие това́ра в приложе́нии.

Main stresses:

• пере́д
• зака́зом
• лу́чше
• прове́рить
• нали́чие
• това́ра
• приложе́нии

A rough pronunciation guide:

• pye-REET za-KA-zam LOOCH-she pra-VYE-rit na-LEE-chi-ye ta-VA-ra v pri-la-ZHE-ni-yi

The two words learners often want to watch carefully are:

• лучше — the чш combination can be tricky
• в приложении — the ending -ии is pronounced clearly, not swallowed completely