The real cost of free online converters
You need a JPG. You have a HEIC. A search result offers to convert it for free. Before you click upload, ask one question: where does the file go?
This post follows a file through a typical upload-based converter. It also explains why we built Convertur to work differently.
Where your file goes
On an upload-based service, your photo travels to a server run by a company you may not know. It waits in a queue. It gets processed. Then it sits in a storage bucket, often for days.
Along the way, copies of the file can end up in logs, caches and backups you never see. Those systems may sit in a country you didn't pick.
What the terms of service say
Terms of service often give the operator broad rights to process and keep uploaded files. Some also let them analyze the content. Few people read that far. The button says free, after all.
Free usually means the service makes money another way. That might be ads, your attention or the data you hand over.
Questions to ask before you upload
Look for a clear retention period. Find out which country or provider stores the file. Check whether deletion also covers backups. Ask whether the service uses uploads to train models. A vague promise to delete files automatically means less than a stated number of hours and a plain list of every company that touches the file.
Also check whether anyone with the download link can open the result. See if you need an account to delete a job. Find out whether staff or software can scan the content for moderation or ads. A private document deserves more care than a throwaway stock photo.
The local-first alternative
WebAssembly lets a browser run the same codecs a desktop app uses. So the conversion can happen on your own computer or phone. There is nothing to upload and nothing to delete afterward.
With no server in the path, there is no server log and no retention window. No terms of service give anyone rights to your file.
When a server still makes sense
Server conversion is not bad by default. It helps with huge files, team workflows, scheduled jobs and specialist software that can't run in a browser. What matters is that you know you are making that trade. If you do upload, pick a provider with clear contracts, retention controls and good security.
For everyday format changes, resizing, checking metadata and many document tasks, you usually don't need a server. Modern browsers can do the work locally. That saves upload time and removes one whole copy of the file from the process.
Takeaways
Before you use any converter, find out where the processing happens, what gets kept and who can see it. For personal or confidential files, use a local tool when it supports your format. Keep the original until you have checked the result.
A free tool still costs money to run. Convertur keeps site delivery and anonymous analytics apart from file processing. Your browser downloads our code. Your file and the converted result stay in the tab until you save or share them yourself.
Some files belong to a client or employer, or fall under legal rules. For those, follow the rules of whoever owns the data. Local processing lowers the risk. It does not replace access controls, backups, device security or a contract review when your organization requires one.