Mayhew Labs writes:
Whether you’re a first-time circuit board designer or you’ve been doing it for years, you know how difficult it can be to visualize layout, spacing, and relative size in PCB layout software. You might have also experienced that uneasy “I hope everything is right” feeling when you submit your design files for manufacturing. You’re not alone! I’ve ordered boards with silkscreen text way too small to read, components on the wrong side of the board, and even had my silkscreen and soldermask layers reversed by mistake! Each of these times, the real problem was not having a good view of the design.View Your PCB Design in 3D Online for Free - [Link]
I came up with a solution to these problems and designed (with the help of a web developer) an online 3D Gerber viewer that anyone can use. If you’re not familiar with Gerber files, they are the files that layout software (like Eagle, Altium, etc) export for manufacturing. They describe everything pertinent about your board that will be required to actually create your PCB.