Privacy Comparison: How File Converters Handle Your Data
Most online file converters upload your files to their servers. Some promise to delete them after 24 hours. Some don't say what happens at all. Here is a side-by-side look at what actually happens to your files when you use the most popular converters.
Data last verified: March 2026. Sources linked below.
The core difference
ConvertSafe converts files in your browser. Your files never leave your device. CloudConvert, Convertio, iLovePDF, and Zamzar upload your files to their servers for processing. That is a fundamentally different approach to privacy, and it is why ConvertSafe exists.
Why this matters
According to a 2024 IBM report, the average cost of a data breach reached $4.88 million globally. When you upload files to a server, you are trusting that server to handle your data securely, delete it when promised, and not suffer a breach. A 2023 Pew Research study found that 79% of Americans are concerned about how companies use their data. With browser-based conversion, these risks do not apply: your files never leave your device, so there is nothing to breach.
| Converter | Files Uploaded? | Tracking | Server Location | Deletion Policy | Verifiable? | Account Required? | Works Offline? | Free Tier |
|---|---|---|---|---|---|---|---|---|
| ConvertSafe | No | Minimal | None (browser-only) | Nothing to delete. Files never leave your device. | DevTools Network tab | No account needed | Yes | Unlimited, no account needed |
| CloudConvert | Yes | Yes | Germany (Hetzner, AWS EU) | Files deleted after 24 hours (per their FAQ). No independent audit confirms this. | No | Free tier: no account. API access requires account. | No | 25 conversions/day, 1 GB max |
| Convertio | Yes | Yes | Not disclosed publicly (as of March 2026) | Files deleted after 24 hours (per their privacy policy). No independent audit confirms this. | No | No account for basic use. Account for higher limits. | No | 100 MB per file, 10 minutes of conversion |
| iLovePDF | Yes | Yes | Spain (Barcelona, EU servers) | Files deleted after 2 hours (per their privacy policy). Premium users can delete immediately. | No | No account for basic use. Account for premium features. | No | Limited free operations per day, file size limits |
| Zamzar | Yes | Yes | United Kingdom | Free files deleted after 24 hours. Paid plans retain files longer for convenience. | No | Email required to receive converted files on free tier. | No | 50 MB per file, 2 files at once |
| VERT.sh | Partial | Minimal | Server used for video only (GPU server) | Video files deleted after 1 hour. Images, audio, and documents are not uploaded at all. | Open source + DevTools | No account needed | No | Free, open source (AGPL-3.0) |
ConvertSafe
- Files uploaded?
- No
- Tracking?
- Minimal
- Server
- None (browser-only)
- Deletion policy
- Nothing to delete. Files never leave your device.
- Verifiable?
- DevTools Network tab
- Account required?
- No account needed
- Works offline?
- Yes
- Free tier
- Unlimited, no account needed
- Encryption
- Not applicable. Files never leave your device, so there is nothing to encrypt in transit.
All conversions run in your browser using JavaScript, the Canvas API, and WebAssembly. You can verify this in the Network tab of DevTools.
CloudConvert
- Files uploaded?
- Yes
- Tracking?
- Yes
- Server
- Germany (Hetzner, AWS EU)
- Deletion policy
- Files deleted after 24 hours (per their FAQ). No independent audit confirms this.
- Verifiable?
- No
- Account required?
- Free tier: no account. API access requires account.
- Works offline?
- No
- Free tier
- 25 conversions/day, 1 GB max
- Encryption
- TLS in transit. Files are decrypted on their servers for processing.
Server-side processing. Files are uploaded, processed on their infrastructure, and stored temporarily. GDPR compliant but your files do sit on their servers.
Convertio
- Files uploaded?
- Yes
- Tracking?
- Yes
- Server
- Not disclosed publicly (as of March 2026)
- Deletion policy
- Files deleted after 24 hours (per their privacy policy). No independent audit confirms this.
- Verifiable?
- No
- Account required?
- No account for basic use. Account for higher limits.
- Works offline?
- No
- Free tier
- 100 MB per file, 10 minutes of conversion
- Encryption
- TLS in transit. Files are decrypted on their servers for processing.
Server-side processing. One of the most popular converters (~22M monthly visits) but every file is uploaded to their servers for conversion.
iLovePDF
- Files uploaded?
- Yes
- Tracking?
- Yes
- Server
- Spain (Barcelona, EU servers)
- Deletion policy
- Files deleted after 2 hours (per their privacy policy). Premium users can delete immediately.
- Verifiable?
- No
- Account required?
- No account for basic use. Account for premium features.
- Works offline?
- No
- Free tier
- Limited free operations per day, file size limits
- Encryption
- TLS in transit, encryption at rest claimed. Files are decrypted for processing.
The largest PDF-focused converter with 226M+ monthly visits. Strong in non-English markets. All files are uploaded to their EU-based servers.
Zamzar
- Files uploaded?
- Yes
- Tracking?
- Yes
- Server
- United Kingdom
- Deletion policy
- Free files deleted after 24 hours. Paid plans retain files longer for convenience.
- Verifiable?
- No
- Account required?
- Email required to receive converted files on free tier.
- Works offline?
- No
- Free tier
- 50 MB per file, 2 files at once
- Encryption
- TLS in transit. Files are decrypted on their servers for processing.
One of the oldest online converters (founded 2006). Supports 1,100+ formats but uploads everything to their servers.
VERT.sh
- Files uploaded?
- Partial
- Tracking?
- Minimal
- Server
- Server used for video only (GPU server)
- Deletion policy
- Video files deleted after 1 hour. Images, audio, and documents are not uploaded at all.
- Verifiable?
- Open source + DevTools
- Account required?
- No account needed
- Works offline?
- No
- Free tier
- Free, open source (AGPL-3.0)
- Encryption
- Not applicable for client-side conversions. Video uploads use TLS.
Images, audio, and documents convert client-side via WebAssembly. Video is the exception: it gets uploaded to an RTX 4000 Ada GPU server for transcoding. Open source, so you can verify the code.
Tracking and encryption: the details
| Converter | Analytics & Tracking | Encryption |
|---|---|---|
| ConvertSafe | None. Cookieless, privacy-respecting analytics (Umami) for page views only. No cookies, no fingerprinting, no ad networks. | Not applicable. Files never leave your device, so there is nothing to encrypt in transit. |
| CloudConvert | Google Analytics, cookies, and third-party scripts. | TLS in transit. Files are decrypted on their servers for processing. |
| Convertio | Google Analytics, cookies, and advertising trackers. | TLS in transit. Files are decrypted on their servers for processing. |
| iLovePDF | Google Analytics, cookies, advertising and marketing trackers. | TLS in transit, encryption at rest claimed. Files are decrypted for processing. |
| Zamzar | Google Analytics, cookies, and third-party scripts. | TLS in transit. Files are decrypted on their servers for processing. |
| VERT.sh | Self-hosted Plausible (cookieless, GDPR-compliant). No third-party trackers. Opt-out available. | Not applicable for client-side conversions. Video uploads use TLS. |
What "privacy" actually means for each converter
ConvertSafe
Your files are read into your browser's memory using the File API. Image conversions use the HTML Canvas element. Data format conversions (CSV, JSON, XML, YAML) use JavaScript parsing. PDF text extraction uses pdf.js, the same library built into Firefox. The converted output is generated as a Blob URL in memory and downloaded directly.
At no point does any file data leave your browser. There is no server endpoint that accepts file uploads. There is no temporary storage. There is nothing to delete because nothing was ever sent.
ConvertSafe uses Umami for anonymous page view analytics. Umami is cookieless, does not fingerprint users, does not collect personal data, and is GDPR/CCPA/PECR compliant without requiring cookie consent banners. Only aggregated page view counts are collected, never file contents or metadata.
You do not have to take our word for it. Open DevTools, go to the Network tab, run a conversion, and look at the requests. You will see page assets loading (JavaScript, CSS, fonts) but zero file upload requests. That is verifiable proof.
CloudConvert
CloudConvert uploads your file to their servers in Germany (Hetzner and AWS EU). The file is processed server-side and the result is made available for download. They state that files are deleted after 24 hours. Their site uses Google Analytics and sets cookies for tracking.
CloudConvert is GDPR compliant, ISO 27001 certified, and transparent about their infrastructure. They have been around since 2012 and have a solid reputation. If you need a format ConvertSafe does not support (like video transcoding), CloudConvert is a reasonable choice. But for image, data, and document conversions that can run in the browser, there is no reason to send your files to their servers.
Convertio
Convertio uploads files to their servers for processing. Their privacy policy states files are deleted after 24 hours. As of March 2026, they do not publicly disclose where their servers are located. Their site runs Google Analytics and advertising trackers.
Convertio is one of the most popular converters on the internet with around 22 million monthly visits. It supports 300+ formats. But every single conversion goes through their servers. For a quick JPG to PNG or CSV to JSON where the browser can handle it natively, uploading your file to a remote server is unnecessary.
iLovePDF
iLovePDF is the largest PDF-focused converter with over 226 million monthly visits. All files are uploaded to their servers in Spain (EU-based). They claim files are deleted after 2 hours, which is shorter than most competitors. Their site uses Google Analytics, advertising trackers, and marketing cookies.
iLovePDF is GDPR compliant and offers a comprehensive PDF toolkit (merge, split, compress, convert, sign). For complex PDF operations that require server-side processing, iLovePDF is a widely used option. For basic conversions like PDF to text or PDF to image that can run in the browser, uploading your documents is an unnecessary privacy trade-off.
Zamzar
Zamzar has been around since 2006 and supports over 1,100 formats. All conversions are server-side. Files are uploaded to servers in the United Kingdom. Free tier files are deleted after 24 hours, but paid plans retain files longer. Their free tier requires an email address to receive converted files. Their site uses Google Analytics and third-party cookies.
Zamzar is a trusted name with a long track record and broad format support. But the trade-off is clear: your files are processed on someone else's infrastructure, and your email address is collected even for free use.
VERT.sh
VERT.sh is the closest competitor to ConvertSafe in terms of privacy. Images, audio files, and documents are converted client-side in the browser using WebAssembly. Video is the exception: it is uploaded to an RTX 4000 Ada GPU server for transcoding and deleted after 1 hour.
VERT.sh is open source under AGPL-3.0, so you can inspect every line of code and verify their claims. They use self-hosted Plausible analytics (cookieless, no fingerprinting, GDPR-compliant) with an opt-out option in settings. No Google Analytics, no advertising trackers. They hit #1 on Hacker News in December 2025 and have 14,000+ GitHub stars. For images, data, and documents, both VERT.sh and ConvertSafe convert locally.
Which converter should you use?
Converting personal photos (HEIC, JPG, PNG, WebP)
Use ConvertSafe or VERT.sh. Your personal photos should not be on someone else's server. Both tools convert images entirely in your browser.
Converting data files (CSV, JSON, XML, YAML)
Use ConvertSafe. Most privacy-first converters focus on media files. ConvertSafe is one of the few that handles structured data formats in the browser.
Handling HIPAA, NDA, or legally sensitive documents
Use ConvertSafe. When files never leave your device, there is no third-party data processing to worry about. No server means no data processing agreement needed, no breach disclosure risk, and no chain of custody questions.
Need video transcoding or 1,000+ formats
Use CloudConvert or Zamzar, and accept the privacy trade-off. Some conversions genuinely require server-side processing. VERT.sh is a good middle ground for video if you want minimal server involvement.
For professionals: why the processing model matters
If you work with sensitive files — medical records, legal contracts, financial statements, HR documents, client data under NDA — the distinction between server-side and browser-based conversion is not just a preference. It is a compliance consideration.
When you upload a file to CloudConvert, Convertio, iLovePDF, or Zamzar, that file is transmitted to and processed on a third-party server. Under regulations like GDPR, HIPAA, and CCPA, this constitutes third-party data processing, which may require a Data Processing Agreement (DPA), consent from the data subject, documentation in your processing records, and breach notification obligations if the processor is compromised.
With ConvertSafe, none of this applies. Your files are processed in your browser. No third-party ever touches the data. This eliminates an entire category of compliance overhead. For teams handling sensitive data, that distinction can save significant time, legal cost, and risk.
How to verify privacy claims yourself
Do not trust any converter's privacy claims at face value, including ours. Here is how to check for yourself:
- Open your browser's DevTools (F12 or Cmd+Option+I on Mac).
- Go to the Network tab and make sure recording is on (the red dot should be active).
- Clear any existing requests so you start with a clean slate.
- Drop a file into the converter and click Convert.
- Look at the Network tab. For ConvertSafe, you will see zero requests that contain your file data. For server-based converters like CloudConvert or Convertio, you will see a large POST request uploading your file.
- Check the request size. Sort by size (largest first). If a request is roughly the same size as your file, your file was uploaded. On ConvertSafe, the largest requests will be JavaScript libraries (under 500 KB) — never your file data.
This test takes 30 seconds and gives you a definitive answer. No marketing copy needed.
Common questions
Is it really safe to convert files online?
It depends entirely on whether the converter uploads your files. Server-based converters like CloudConvert, Convertio, iLovePDF, and Zamzar send your files over the internet to their servers. That means your files exist on infrastructure you do not control, even if temporarily. Browser-based converters like ConvertSafe process files locally. Your files never leave your device. For sensitive documents, financial data, personal photos, or anything under NDA, the distinction is significant.
What is client-side file conversion?
Client-side conversion means your file is processed entirely within your web browser using JavaScript, the Canvas API, or WebAssembly. The file is read into your browser's memory, converted, and the result is downloaded directly. At no point is any file data sent to a server. This is fundamentally different from server-side conversion, where your file must be uploaded to a remote server for processing.
Can browser-based converters handle large files?
Yes. For typical image and data conversions, browser-based processing is fast on modern hardware. Very large files may be slower on older devices because the processing uses your device's CPU and memory instead of a server. For most users, the difference is negligible, and the privacy benefit outweighs the speed difference.
Why do most converters still upload files to servers?
Two reasons. First, some formats genuinely require server-side processing. Video transcoding, OCR, and complex document conversions often need more resources than a browser can provide. Second, server-side processing was the only option when most of these tools were built. CloudConvert launched in 2012 and Zamzar in 2006. Browser APIs have improved dramatically since then. The Canvas API, WebAssembly, and libraries like pdf.js make it possible to handle many conversions locally that used to require a server.
What formats does ConvertSafe support?
ConvertSafe supports conversions across images (JPG, PNG, WebP, BMP, GIF, SVG, HEIC), data formats (CSV, JSON, XML, YAML), and documents (PDF, Markdown, TXT). All run entirely in the browser. New formats are added regularly. Check the full list of converters for the current list.
What happens to my files on CloudConvert after 24 hours?
CloudConvert states that files are automatically deleted after 24 hours. However, there is no independent audit or third-party verification of this claim. You are trusting their policy and internal processes. With browser-based conversion, this question does not apply — there is nothing stored on any server to begin with.
Can my employer see files I convert online?
If you use a server-based converter on a corporate network, your employer's network monitoring tools could potentially see that you uploaded a file to that service (and possibly the file itself if TLS inspection is enabled). With browser-based converters like ConvertSafe, no file data is transmitted over the network, so there is nothing for network monitoring to intercept.
Are file converters safe for medical or legal documents?
Uploading medical records (HIPAA), legal contracts, or other regulated documents to a third-party server may create compliance obligations including data processing agreements and breach notification requirements. Browser-based converters eliminate this risk entirely because the file never leaves your device. If you handle regulated data, the processing model of your converter matters.
Does ConvertSafe work offline?
After your first visit, most converters work offline thanks to service worker caching. The exception is PDF-related conversions, which require the pdf.js library to be loaded at least once while online. This offline capability further reinforces the privacy model: if it works without internet, your files obviously cannot be uploaded anywhere.
Is VERT.sh really private for video?
For images, audio, and documents, VERT.sh is fully client-side and private. For video, the file is uploaded to their GPU server for transcoding and deleted after 1 hour. VERT.sh is transparent about this limitation and their code is open source (AGPL-3.0), so you can verify the claim. It is a reasonable trade-off given that video transcoding is extremely resource-intensive for browsers.
Sources
- CloudConvert Privacy Policy: cloudconvert.com/privacy
- Convertio Privacy Policy: convertio.co/privacy
- iLovePDF Privacy Policy: ilovepdf.com/help/privacy
- Zamzar Privacy Policy: zamzar.com/privacy
- VERT.sh Privacy Policy: vert.sh/privacy | Source code (GitHub)
- IBM Cost of a Data Breach Report 2024: ibm.com/reports/data-breach
- Pew Research Center — How Americans View Data Privacy (2023): pewresearch.org
- iLovePDF traffic data via Semrush: semrush.com