I have a A1458 iPad which has iOS 10.3.3 how can I upgrade this to latest iOS?!

If you have an iPad 4th generation, no.

The iPad 4th generation is ineligible and excluded from upgrading to iOS 11 or iOS 12 and any future iOS versions.

With the introduction of iOS 11, ALL support for older 32-bit iDevice hardware and any iOS 32 bit apps has ended.

An iPad 4 is an older, 32-bit hardware device.

With the introduction of the 64 bit coded iOS 11, and now iOS 12 and later, ALL newer iOS versions will ONLY support newer 64 bit hardware iDevices and 64 bit software, now.

The iPad 4 is incompatible with all of these new iOS versions, now.

No need to panic or worry though.

An iPad 4th gen will still work and function as it always has, but will no longer receive any more app updates sometime in the foreseeable future.

The 4th gen iPad has had over 5 years of iOS upgrades/updates

The final app updates your 4th gen iPad will receive will be its last!

The iPad 4 will survive and stay a viable, functioning iPad for a couple more years.

Currently, iPad 4 models are STILL receiving regular app updates, but look for this change over time.

This is why Apple introduced the new, lower cost 2018 and 2017 iPad 6th and 5th generation models.

Apple is trying to get older iPad 2, 3, 4 and 1st gen Mini iPad users to upgrade to more modern iPad hardware in anticipation of the recent releases of iOS 11, and now iOS 12, which will render all older 32 bit iDevices obsolete, in time.

Also, since the iPad 4 has not had any new iOS upgrades/updates in over a year, I would strongly consider you stop using that year old, default iOS Safari Web browser and seek out other more current and, up to date and more secure third party Web browsers, instead.

Here are a few, more popular, third party web browsers that I know are STILL being updated and supported on iOS 10 and earlier.

Firefox Web browser

Google Chrome browser

iCab Mobile Web browser

Dolphin Web browser

Dolphin Incognito Web browser

DuckDuckGo private Web browxer

Snow Bunny Web browser

Private Browsing Web browser

Aloha Web browser

Maxthon Web browser

Also, there is no longer any way to get iOS 11, any longer. Apple has moved on to iOS 12, now.

Sorry & Good Luck to You!

That's a 4th gen iPad, iOS 10.3.3 is the highest iOS version it supports, you can't update to it iOS 11 or higher

Only if your iPad supports a newer iOS version which it probably doesn’t since you are still on 10.3. Read the thread. Which iPad do you have?

If no joy,

There are a handful of word processing apps in the iOS App Store that should be compatible with Microsoft Word.

Look at

Bear

iA Writer

Mellel ( this iOS word processing app maybe better now as its devs issued a recent update to app back in Nov. 2018

Scrivener

Textilus

Ulysses

Wordsmith

Also various, comprehensive Notes apps in the iOS App Store, too!

Best of Luck to You!

Can I upgrade iOS 10.3 to iOS 11?

If the apps are in your account's purchase history (e.g. if you've downloaded them on your computer's iTunes, if you haven't updated to iTunes 12.7+, or on another iOS device that's on iOS 11+) you could see if you can download an older compatible version of them via the Purchased tab in the App Store app

Microsoft just recently removed all of their older apps from the iOS App Store.

So, getting older iOS versions of Microsoft apps is impossible now.

Also, if your iPad does not have Apple’s iOS versions of their iWork apps ( Pages, Numbers and Keynote ) getting older versions of these apps could prove problematic, now, also.

Try this.

If you need older versions of apps that have moved on to iOS 10 and later, tap on my link below and choose the method that best works with your current situation.

CAREFULLY read and follow ALL directions. Especially so for my computer/older iTunes procedures.

All three of my procedures/solutions work!

Downloading Older iOS 9.3.5 Versions of A… - Apple Community

A Disclaimer.

Apps may or may not have older iOS 9.3.5 versions still available from the iOS App Store.

There are three ways to try/attempt to get an older version of an app. Pick the method that works best for your situation/circumstances.

Also, since the iPad 4 has not had any new iOS upgrades/updates in over a year, I would strongly consider you stop using that year old, default iOS Safari Web browser and seek out other more current and, up to date and more secure third party Web browsers, instead.

Here are a few, more popular, third party web browsers that I know are STILL being updated and supported on iOS 10 and earlier.

Firefox Web browser

iCab Mobile Web browser

Dolphin Web browser

Dolphin Incognito Web browser

DuckDuckGo private Web browxer

Snow Bunny Web browser

Private Browsing Web browser

Aloha Web browser

Maxthon Web browser

Good Luck to You!