Convert files on Android without uploading, and with no app to install

Why Android converter apps are the wrong default

Search the Play Store for a file converter and you get a wall of free apps, and the business model behind most of them is the problem. The common pattern is one of two things, often both. Either the app is ad-supported to the point of being unusable, throwing a full-screen ad between you and every conversion, or it asks for broad permissions on install: access to all your photos and media, storage, sometimes contacts or device identifiers that a format converter has no honest reason to need. And under the hood, a large share of these apps do not convert on the phone at all. They upload your file to a server, convert it there, and hand back a download, which means a copy of your file briefly lives on a machine you cannot see.

That last part is exactly what the FBI warned about. In March 2025 the agency publicly flagged free online file-converter services as a common vector for malware and data theft, precisely because they route your files through opaque servers. The file you are converting on a phone is often the most personal thing you own: a photo of a document, a voice memo, a screenshot of a bank statement. Handing it to an ad-funded app with all-photos permission is the worst available answer. The point of this page is that you do not need an app at all.

How the browser converts on your phone with nothing installed

hushvert is a website, not an Android app, and that is the whole design. There is no APK to sideload, no Play Store listing, no permission prompt for your photos, and nothing left running in the background after you close the tab. It works in the browser you already have, mobile Chrome or Firefox (and other modern Android browsers built on the same engines), with no setup.

When you tap to add a file, your phone's browser fetches a WebAssembly build of the conversion engine once, then runs it on your file inside the sandboxed tab, on your phone's own processor. There is no upload step because no server is doing the work. The result is saved to your phone the way any browser download is, to your Downloads, where your gallery and file manager can pick it up. The first conversion in a session downloads the engine; after that it is cached, so repeat conversions on the same phone start instantly. Because it is a web page and not an installed binary, it requests no special permissions and reads nothing it is not handed directly.

Converting HEIC on Android, which is genuinely awkward

HEIC is the sharpest Android pain point, so it is worth being precise. Android has no single, universal one-tap HEIC-to-JPG export that exists on every device. Some manufacturer galleries do include an option (certain Samsung Gallery and Google Pixel builds let you save or share a HEIC photo as JPG), but it is inconsistent across brands, Android versions, and gallery apps, so the steps a friend tells you may not exist on your phone at all. When an AirDropped or downloaded .heic file from an iPhone lands on your Android device and nothing opens it cleanly, that gap is what sends people to a sketchy converter app.

The browser route closes the gap the same way on every Android phone. Add the .heic file to hushvert and convert it to JPG, PNG, WebP, or AVIF entirely in your phone's browser. A WebAssembly HEIC decoder runs on your device, so the photo never uploads. There is a deliberate design choice behind this: HEIC is never processed on a server here, even though a server lane exists for other tasks, because HEIC relies on HEVC and its patent constraints, so decoding always stays client-side. As a side effect of decoding to raw pixels, EXIF metadata such as GPS coordinates is dropped from the output rather than carried along. Start with HEIC to JPG for the universal, shareable result, or HEIC to PNG when you want lossless output for editing.

Everything else you can convert in the Android browser

HEIC is the headline, but the no-upload browser lane on your phone covers a lot more, and all of it is free and unlimited with no account.

Images: convert between JPG, PNG, WebP, and AVIF in any direction, plus BMP and TIFF to JPG or PNG, SVG to PNG or JPG, JXL to and from JPG and PNG, and PNG or JPG to ICO. You can also compress a JPG or PNG to a smaller file. A precise note: converting to a lossy target such as JPG, or WebP and AVIF at lossy settings, re-encodes the image, and PNG to JPG also drops transparency; PNG, TIFF, and BMP are lossless. Do not expect every image format to convert to every other, only JPG, PNG, WebP, and AVIF fully interchange.

Audio: roughly 18 conversions across MP3, WAV, FLAC, OGG, M4A, AAC, AIFF, and WMA, plus extracting an MP3 audio track from an MP4, MOV, MKV, WebM, or AVI video, handy for pulling the sound out of a clip you recorded. Lossless-to-lossless conversions preserve samples exactly; converting to a lossy target like MP3 genuinely re-encodes, which is true of any MP3 encoder.

Archives: pack and unpack ZIP, TAR, and TGZ files in the browser, useful when an Android file manager will not open a TAR or TGZ natively.

PDF page operations: merge several PDFs into one, turn PDF pages into JPG or PNG images, extract a PDF's text, and build a PDF from JPG, PNG, SVG, or text. To be precise about the edges, there is no one-click PDF compressor and no PDF split or reorder tool, so we will not pretend those exist. Small video re-encoding also runs in the browser; very large video is the labeled server exception below.

Batch conversion on a phone, and what to expect

You are not limited to one file at a time. You can add several files at once from your phone's picker or file manager and convert them in a batch, which is the realistic case when you are clearing a folder of iPhone photos off an Android device or converting a set of voice memos. Each file is processed locally in turn and saved to your Downloads, with nothing uploaded at any point.

The honest tradeoff on mobile is processing power and memory. Conversions run on your phone's own CPU, so a large batch, a long uncompressed WAV, or a high-resolution image set takes longer on a phone than on a laptop, and a very large file can bump into the browser's memory ceiling on an older or budget device. Keep the screen awake while a big batch runs, since backgrounding the browser tab can pause the work. For everyday batches of photos, audio, and PDFs this is a non-issue; for a one-time conversion of dozens of large files, a desktop browser will simply finish faster. None of this changes the privacy guarantee: small or large, batch or single, the files stay on your phone.

Prove nothing uploaded, on the phone in your hand

The whole point is that you do not have to trust a privacy promise, you can check it in under a minute on the exact phone you are holding. There are two ways.

The airplane-mode test is the strongest. Load the converter page, then swipe down to open Android's quick settings and tap Airplane mode so both Wi-Fi and mobile data go off. Now convert a file. It still finishes, because there was never anything to upload. The /privacy-proof page has a built-in airplane-mode demo that walks through exactly this. Note the demo lives on the privacy-proof page, not the homepage.

The network-inspection test is the second check. Mobile browsers do not expose a full Network tab as easily as desktop, so the practical mobile proof is airplane mode; if you want the developer-tools view, connect the phone to a computer and use Chrome's remote debugging to watch the requests, or simply run the same conversion on a desktop browser and open its Network tab. Either way you will see the engine load once and then no request carrying your file bytes. This is not just a marketing line. A CI test runs on every single code change and fails the build if any network request could carry file bytes, so the no-upload behavior cannot silently regress, and the engine is open source under the MIT license (published as @hushvert/engine), so it is auditable rather than merely claimed.

The honest exception: office docs and large video

We will not overclaim. Two categories genuinely cannot run inside a phone's browser tab today, and for those hushvert uses a separate lane that is clearly labeled 'this one leaves your device' before you start.

First, office documents to PDF: DOCX, DOC, XLS, XLSX, PPT, PPTX, ODT, ODS, ODP, RTF, and HTML, plus PDF to Word. High-fidelity office rendering needs a real document engine that does not fit in the browser. Second, very large video that exceeds what a phone's browser can process. These run on a server, and hushvert tells you so up front rather than hiding it.

The server lane is honest about retention: inputs are deleted immediately after conversion and outputs within about an hour. It is free for the first 2 conversions per day anonymously, then a free email account raises that to 5 per day plus 150 MB per day; beyond that you can pay with a $5 Week Pass or credits that never expire, with no subscription. Crucially, none of the client-side conversions above (images, HEIC, audio, archives, PDF page operations) ever touch this lane or count against any quota, and HEIC specifically is never sent to a server under any circumstance. There is no hushvert Android app to install for any of this; it is all the website.

Popular conversions that run on Android

• HEIC to JPG
• JPG to PNG
• PNG to WEBP
• PNG to JPG
• WAV to MP3
• MP4 to MP3

Keep reading

• Convert HEIC to JPG without uploading
• Convert audio without uploading
• Convert iPhone photos without uploading
• See the no-upload proof
• Private file converter

Common questions

Do I need to install an app to convert files on Android this way?

No. hushvert is a website, not an Android app, so there is no APK to download, no Play Store install, and no permission prompt for your photos or storage. You open it in the mobile browser you already have, Chrome or Firefox, add a file, convert, and the result saves to your Downloads. The first conversion in a session fetches a small WebAssembly engine once and caches it; after that, conversions start instantly. There is no hushvert app at all, by design.

How do I convert a HEIC photo to JPG on my Android phone?

Add the .heic file to hushvert in your phone's browser and convert it to JPG, PNG, WebP, or AVIF. A WebAssembly HEIC decoder runs on your own device, so the photo never uploads. This matters on Android specifically because there is no universal one-tap HEIC export on every phone; some Samsung and Pixel galleries include an option, but it is inconsistent across brands and Android versions. The browser route works the same on any Android device, and HEIC is never sent to a server here for patent reasons.

How do I prove the file isn't being uploaded from my phone?

The simplest mobile proof is airplane mode. Load the converter, swipe down and tap Airplane mode so Wi-Fi and mobile data are both off, then convert a file; it still finishes because nothing needs to upload. The /privacy-proof page has a live airplane-mode demo. Mobile browsers do not expose a Network tab easily, so for the developer-tools view you can run the same conversion on a desktop browser and open its Network tab, where you will see the engine load once and no request carrying your file bytes. A CI test also fails the build on any change if a request could carry file bytes.

Can I convert several files at once on mobile?

Yes. You can add multiple files from your phone's picker or file manager and convert them as a batch, with each file processed locally and saved to Downloads, nothing uploaded. The honest tradeoff is speed: conversions run on your phone's CPU, so a large batch or a very large file is slower than on a laptop and can hit the browser's memory ceiling on older or budget devices. Keep the screen awake during a big batch so the tab does not pause.

Why not just use a free converter app from the Play Store?

Many free Android converter apps are heavily ad-supported and request broad permissions, such as access to all your photos and storage, that a format converter has no honest reason to need. A large share of them also upload your file to a server to do the conversion, which is the exact pattern the FBI warned about in March 2025 as a malware and data-theft vector. hushvert avoids all of that: it is a web page, so it installs nothing, requests no permissions, and converts on your device with no upload for the client-side formats.

What can't I convert in the browser on Android?

Office documents to PDF (DOCX, XLSX, PPTX, and similar), PDF to Word, and very large video exceed what a phone's browser tab can do, so those use a separate server lane that is clearly labeled 'this one leaves your device' before you start. On that lane, inputs are deleted immediately after conversion and outputs within about an hour. Everything else (images, HEIC, audio, ZIP, TAR, and TGZ archives, and PDF page operations) runs client-side with no upload. There is no PDF compressor or PDF split tool yet.

Is it free, and is there a file size limit?

All client-side conversions are free and unlimited with no account. Per-file ceilings exist (for example around 200 MB for audio), and because the engine runs on your phone's own processor, large files are slower on mobile than on a desktop. The paid server lane applies only to office documents and very large video: 2 free conversions per day anonymously, then a free email account raises it to 5 per day plus 150 MB per day, then a $5 Week Pass or credits that never expire, with no subscription.