Compress Video Size Compressor

Review by eFreeware

If your phone storage keeps filling up with recorded video, or you regularly need to send clips that are too large for a messaging app or an email attachment, this is the sort of tool worth having installed. Compress Video Size Compressor from Inverse AI is a free Android app for shrinking and converting video files, and it has clearly found an audience: more than 5 million installs and a 4.4 average across 180,441 ratings.

What it offers is control rather than a single magic button. You can pick a preset profile, set a target file size by hand, choose the codec and resolution, preview a short sample of the result before committing, and queue several videos to run one after another. For anyone who treats video as something to store, send and archive rather than to edit, that combination covers most of the everyday jobs.

It has been on Google Play since January 30, 2020, with an update in September 2026, so this is an established utility rather than a new experiment. The app is free, carries ads, and offers in-app purchases.

What shrinking a video actually involves here

The app reads a wide range of containers: MP4, MKV, AVI, 3GP, FLV, MTS, MPEG, MPG, WMV, M4V, MOV and VOB. That matters if your footage comes from different places, since phone recordings, downloaded files and camera exports do not all arrive in the same format. The app converts between formats too, with MP4, MKV, AVI, 3GP, FLV, MTS, M4V and MOV as output options.

Compression itself works two ways. One path keeps the original quality while reducing the file, and the other reduces resolution and bitrate, which visibly lowers quality in exchange for a much smaller result. The app shows an estimated output size for the second approach before you start, so you can judge how much space a given setting will save.

There is also a short preview: the app plays a small sample of the video using the settings you chose, before the full compression runs. That is the feature I would lean on most, because it turns an abstract choice about bitrate into something you can see. You find out whether the result still looks acceptable while the decision is still cheap to change.

Once a file is done, you can play it, share it, or delete either the compressed version or the original from inside the app, which keeps the cleanup in one place instead of sending you to a file manager.

Presets, target sizes and manual settings

The simplest route is a predefined profile. Several are included, each balancing quality against size, and they exist so you do not have to understand codecs to get a reasonable result. If you would rather aim at a number, you can enter the size you want the compressed file to be and let the app work toward it. That is useful when a platform imposes a limit and you need the clip to fit.

For finer control, resolution and bitrate can be set by hand. This is the part that rewards a little patience: lowering resolution cuts size quickly, while bitrate governs how much detail survives in motion. The app shows the estimated size as you adjust, which makes the relationship between the two easier to grasp than it would be in the abstract.

Between the presets and the manual settings, the app covers both the person who wants a decision made for them and the person who wants to make it themselves. I would expect most users to start with a preset, then move to manual settings once they have seen what the preview looks like at a given quality.

Choosing between X264 and X265

Two codecs are offered: X264 and X265, also known as HEVC. The developer describes HEVC as delivering considerably more compression than X264, while X264 is much faster at the job. That is the central trade-off in the app, and it is worth understanding before you queue up a long list of files.

If storage is the priority and you can wait, HEVC is the sensible choice. If you have a batch of clips to get through and time matters more than the last few megabytes, X264 will finish sooner. The app also lets you choose the compression speed itself, with the developer noting that higher speeds produce larger compressed files. So there are two dials pointing in the same direction: speed up the process, and you pay in size.

For a single holiday clip, none of this is worth agonizing over. For a folder of recordings you intend to keep for years, the codec choice is the one that will still matter when you look at the storage figures later.

Batch work and side-by-side checks

Videos can be queued so that several compress in one run rather than one at a time. This is the feature that turns the app from an occasional tool into something you can use to clear a backlog of recordings in an evening, and it is the reason I would consider it for a phone that is chronically short on space.

There is also a comparison view that plays the original and the compressed file at the same time on one screen. Watching them together is a more honest check than watching each separately, because differences in motion and fine detail are easier to spot when the two run in parallel. If you are compressing something you care about, this is the step that tells you whether you went too far.

An assistant called IVA is included, along with a media picker that remembers your sort setting, plus stability and interface improvements. The sort memory is a small thing, but it is the kind of detail that matters once you are working through a long list of files.

Format conversion and what it costs you

Conversion goes beyond compression. The app is free to download, shows ads, and offers in-app purchases, so some capabilities sit behind payment.

The other cost is time and quality, and the app is fairly open about both. Reducing resolution and bitrate does not preserve the original quality, as the developer puts it, and the faster you push the compression, the larger the file you end up with. The preview and the estimated size exist precisely because those trade-offs are real and vary from clip to clip.

The app is marketed as the top video compressor and converter available. I would treat that as marketing rather than a measurement. The app offers a broad set of manual controls, which is a more useful thing to judge it on than a superlative.

Who this suits

This is for people who record a lot of video on their phone and need the files to take up less room, or who regularly have to send clips that are too big to go through as they are. It is also for anyone who receives video in formats their phone will not play or share, and needs a straightforward way to convert them.

It is built for users who want to see the numbers: estimated size, resolution, bitrate, codec. Someone who wants a single button and no decisions will still find the presets, but the app's character is one of options and previews. If you would rather not think about codecs at all, the preset route and the preview clip will carry you most of the way.

The audience most likely to get value from it is the person treating their phone as the place where video lives, rather than the person editing footage for publication. Free with ads and optional purchases, it fits that role without asking for much.

A practical tool for a phone short on space

Compress Video Size Compressor does one job with an unusual amount of control for a free Android app. Presets, target sizes, manual resolution and bitrate, a codec choice between X264 and X265, a preview sample, batch queuing and a side-by-side comparison cover the decisions that actually affect how a video turns out. The wide format support means it can handle whatever your phone, camera or downloads throw at it.

The caveats are the ones the app itself sets out. Compression costs either quality or time, conversion to the listed output formats is a PRO feature, and the app carries ads. None of that is hidden, and the preview exists so you can see the result before you commit to it.

If you need to free up storage, send smaller clips or convert files into a format your devices accept, this is a reasonable thing to install. It suits people who want to make the quality-versus-size decision themselves and see the estimate before they press go.

What's new in version 21.6.0

+ Added IVA, our AI Assistant, to make Video Compression Smarter, Faster, and Easier. + Media Picker now remembers your sort setting + Stability Enhancement + UI Improvements