A vector artwork file holds editable paths in a proprietary structure. Whether anything else can read it depends on one setting that was chosen when it was saved.
The PDF inside
When saved with PDF compatibility enabled, which is the default, the file contains a complete readable PDF alongside the editable data.
That is why a document reader sometimes opens one and why renaming the extension frequently works.
Rename a copy, not the original. If it opens, you can view and print it, and you cannot edit the vectors usefully.
If it shows nothing, the file was saved without that option and you need something that understands the native structure.
| Route | Can view | Can edit | Uploads anywhere |
|---|---|---|---|
| Rename to PDF | Usually | No | No |
| Free vector editor | Yes | Mostly | No |
| Online converter | Yes | No | Yes |
| Original software | Yes | Fully | No |
Free vector editors
These open most artwork files and edit the paths.
What differs: fonts not installed are substituted, some effects render differently or not at all, and certain features do not survive being saved and reopened elsewhere.
For viewing, measuring, extracting a shape or checking a colour, that is fine. For work going back to a designer, expect them to notice.
The upload question
An online converter receives a complete copy of the artwork.
For a personal project, a reasonable trade. For a client's logo before launch, a brand identity under agreement, or anything unreleased, it is confidential creative work handed to a company you have not evaluated.
A free local editor does the same job without that.
What you probably actually need
Most people opening one of these are approving a design rather than editing it.
For that, the artwork file is the wrong artefact entirely. An SVG scales and opens in any browser. A PNG opens anywhere at all. Either is a better thing to receive and a smaller thing to send.
Tell the designer
Designers send the working file out of habit, the way people attach editable documents when a PDF would do.
Ask once: an SVG or a PNG for review, the editable file only for production. It is less work for them too, and it removes the whole question from the next project.
For the surrounding ground, see How to open a PSD file without Photoshop and How to host an SVG file.
Put it at an address
Try renaming to PDF, use a free vector editor if that fails, expect substituted fonts, keep client artwork off online converters, and ask for an export when you are approving rather than editing.
Then opening artwork stops depending on which software you happen to own.