Browser privacy guide: keep your data on your device

What does ‘files never leave your device’ mean?

When this site says a tool processes files in your browser, it means the file’s bytes are read into your device’s memory by JavaScript running locally, transformed locally, and the result is saved back to your device — with zero network requests carrying your file anywhere.

Try it: merge two PDFs with the Network tab open and watch — nothing uploads. You can verify this yourself: open your browser’s developer tools, watch the Network tab while compressing an image, and see that no file upload occurs. Contrast the alternative: upload-based tools send your file to a server (visible as a large POST request in that same Network tab), process it there, and return the result. Your document then exists on someone else’s infrastructure — subject to their security, their retention policy, and their business incentives. For a meme that hardly matters; for a salary slip, medical scan or contract, the difference is everything.

This architecture is also why the tools need no sign-up: there’s no server-side processing to bill you for and no account needed to associate files with. Privacy and the business model are the same engineering decision, which is exactly why you should prefer tools where they coincide.

What do cookies actually do?

A cookie is a small text file a website asks your browser to store and send back on future visits. Essential cookies keep sites working (remembering consent choices, keeping you logged in). Analytics cookies measure aggregate usage (“how many people visited this page”). Advertising cookies — the controversial ones — let ad networks recognise you across sites to personalise ads.

The realistic assessment: first-party essential cookies are harmless plumbing; analytics cookies are a mild, aggregated privacy cost that funds free content; third-party advertising cookies are the genuine concern, building cross-site profiles of your browsing. This site uses consent management — you choose whether analytics and advertising storage are granted — and advertising here is contextual (based on the page, not on you).

Practical cookie hygiene: accept essential, decide on analytics per your comfort, and clear third-party advertising cookies periodically (browser settings → privacy → clear cookies, or an extension that auto-clears them). Don’t obsess: cookie management is one slice of privacy, and the trackers that matter most aren’t defeated by cookie-clearing alone.

What does incognito mode actually protect?

Incognito/private mode does exactly one thing: it doesn’t save browsing history, cookies or form data on your device after the session ends. That’s it. It does not hide your activity from your internet provider, your employer’s network, the websites you visit, or anyone monitoring the network. The name “incognito” wildly oversells it.

Its genuine uses: logging into two accounts simultaneously, shopping for gifts on a shared computer, testing how a site looks logged-out, and keeping casual local privacy from people who share your device. For those, it’s perfect. As a shield against tracking, it’s nearly useless — trackers use IP addresses, browser fingerprinting and logged-in sessions, none of which incognito touches.

The myth persists because it feels private — the dark window, the warning page. Judge privacy tools by mechanism, not by theatre: ask “who can still see this?” for every claim. Incognito’s honest answer (“everyone except people with physical access to this device afterwards”) is useful once you know it.

Which browser settings genuinely improve privacy?

In order of impact: 1. Block third-party cookies (now default in most browsers) — cuts the main cross-site tracking vector. 2. Use tracking protection / “do not track” plus an ad-blocker — blocks most tracker scripts outright; this single step does more than all cookie management combined. 3. Review site permissions (camera, microphone, location) — set to ask-by-default and grant sparingly. 4.

Keep the browser updated — most “hacking” exploits patched vulnerabilities, not clever tricks. Then the account layer: don’t stay logged into Google/Facebook while browsing generally — logged-in sessions are the highest-fidelity tracking there is, far beyond cookies. Use separate browser profiles (or containers) for logged-in services versus general browsing. And use unique passwords everywhere via a password generator and a password manager — credential reuse remains the top account-takeover vector.

On phones: review app permissions with the same scepticism (why does a flashlight need contacts?), prefer the browser over apps for casual services (apps collect far more — device IDs, location, sensor data), and keep the OS updated. Mobile privacy is mostly app hygiene, not browser settings.

• Third-party cookies blocked; tracker-blocking enabled
• Site permissions (camera/mic/location) on ask-by-default
• Separate profiles: logged-in services vs general browsing
• Unique passwords via generator + manager; browser always updated

What about VPNs, extensions and ‘private’ browsers?

VPNs hide your traffic from your local network and ISP and change your apparent location — genuinely useful on public Wi-Fi and for location privacy. They do not make you anonymous to websites (fingerprinting, logged-in accounts) and they shift trust from your ISP to the VPN provider — choose reputable ones, since a malicious VPN sees everything.

Extensions: ad/trackers blockers are the highest-value installs; beyond that, every extension is code with broad permissions — install few, from known developers, and review permissions yearly. Private browsers (Brave, Firefox with hardening, Tor for extreme cases) offer real improvements — fingerprinting resistance, aggressive tracker blocking — but with compatibility trade-offs. For most people, a mainstream browser with tracking protection, an ad-blocker and sane settings captures 80% of the benefit with 0% of the friction.

The meta-rule: every privacy tool moves trust, it doesn’t eliminate it. VPN moves trust to the provider; private browsers move trust to their developers; extensions move trust to their authors. Prefer tools whose business model doesn’t depend on your data — incentives predict behaviour better than promises.

What are the honest limits of browser privacy?

Say it plainly: a browser cannot protect you from yourself. Phishing — fake login pages, urgent messages, too-good offers — bypasses every technical control by targeting the human. No setting compensates for entering your bank password into a linked page you didn’t verify. Skepticism about unsolicited messages is the highest-value privacy tool in existence, and it’s free.

Second limit: the services you log into. Google, Meta, your bank — once authenticated, they see what you do on their platforms by design. Browser privacy controls the unseen tracking; your chosen relationships are governed by those companies’ policies and your settings within them. Audit those yearly: ad preferences, data-sharing toggles, connected apps.

Third: your network sees metadata (which sites, when, how much) unless you use a VPN or Tor — and your employer’s network sees everything on work devices by policy. Curious what that baseline looks like? Check your public IP and browser details — that is the metadata every site sees on every visit. The realistic goal was never invisibility; it’s appropriate visibility: essential cookies for sites you use, no cross-site profiling by strangers, your files staying on your device, and accounts only where they earn their keep. That’s achievable, and this guide is the map.

• Skepticism beats software: verify before you log in anywhere
• Audit logged-in services’ privacy settings yearly
• Goal: appropriate visibility, not invisibility
• Files on your device + no unnecessary accounts = the foundation