Download means bringing a file from somewhere else onto your own device; upload means sending a file from your device out to a server or service. I downloaded the invoice from the bank's website. I uploaded my passport photo to the application form. The direction is always described from your device's point of view.
The core difference
Both words describe the same action — a file moving across a network — and differ only in direction. The reference point is always you: your phone, your laptop, the machine in front of you.
- Download: remote → yours. The file arrives.
- Upload: yours → remote. The file leaves.
The up and down have nothing to do with your screen. They come from an older way of picturing networks, with big central computers "up" at the centre and small ones "down" at the edges.
How to use each
- Download the app before you get on the plane.
- The report took ten minutes to download over hotel wifi.
- Upload your CV using the button at the bottom of the form.
- You can upload up to 50 photos per album.
The test you can run
Ask one question: where does the file end up? If it ends up on your device, you downloaded it. If it ends up somewhere you would need the internet to reach again, you uploaded it.
A shortcut for the awkward cases: if you are giving the file to someone else, it is an upload. If you are getting a file for yourself, it is a download.
Common mistakes
The most frequent error is "download it to the website" or "can you download the photos to me?" when the speaker means upload or simply send. The giveaway is the destination — if the file is going away from you, download is the wrong word.
Prepositions help keep it straight:
- Download from a site, download to your computer.
- Upload to a site, upload from your computer.
The edge cases
Email attachments. Attaching a file to an email uploads it; opening an attachment someone sent you downloads it. People rarely say so, but that is what is happening.
Cloud sync. Services like a shared drive do both continuously, which is why neither word fits a synced folder well. Say sync.
Streaming. Watching a video streams it rather than downloading it: the data arrives but is not kept as a file you own. "Download for offline" is the separate action of saving a copy.
Speed figures. Home broadband is usually much faster down than up, which is why sending a large video takes longer than receiving one of the same size. If someone quotes a single broadband speed, they almost always mean the download figure.
Both words work as nouns too: "a slow download", "the upload failed". Write them as one word — down load and up-load are outdated.
Frequently Asked Questions
Do I upload or download a file to send it to someone?
You upload it. Anything that leaves your device for a server, a website or a shared drive is an upload; download only describes a file coming towards you.
Is attaching a photo to an email uploading?
Yes. The photo travels from your device to the mail provider's servers, which is an upload — it just happens quietly in the background while you write the message.
Why is my upload speed slower than my download speed?
Most home connections are deliberately asymmetric, because typical users receive far more data than they send. That is why a large video takes longer to send than to receive, even on a fast connection.