Yes, both LibPixel and Pixelshift.io offer a Free Trial.
LibPixel is designed for Freelancers, Large Enterprises, Medium Business and Small Business.
Pixelshift.io is designed for Large Enterprises, Medium Business and Small Business.
Pricing for LibPixel Starts at $15/Month whereas for Pixelshift.io Starts at $10Per Hour.
Some top alternatives to LibPixel includes Resizing.app, Pixelz, Resizer, Cloudimage.io, ShortPixel, ShortPixel Google Drive Optimizer, Pixelied Convert, ImageBoss, Qualified, Workvivo, Pixelshift.io and IFTTT.
Some top alternatives to Pixelshift.io includes Resizing.app, ClientSuccess, Cloudimage.io, Freshdesk Customer Success (Formely Freshsuccess), ImageBoss, Memer API, Massless, Imagesocket, Base API and LibPixel.