Should I Sell This?
Evaluate price, costs, fees, returns and target margin before deciding whether a proposed sale is worth pursuing.
Guides and tools
Choose the right way to start
Use a tool when you have a specific question to check now. Use a guide when you need context, a sequence of steps or help deciding what comes next.
Start with a tool
Featured tools
Four useful starting points for decisions, profitability, listing text and images.
Prepare a stronger listing
Check title clarity and image dimensions before moving into the wider listing-readiness workflow.
Start with a guide
Featured beginner guidance
Start with one clear route, then continue only to the resources that match your goal.
Start selling online
A beginner guide for choosing a marketplace path and understanding the preparation work ahead.
Prepare your first product
A step-by-step resource path from channel choice and templates to checklists and tools.
Solve a real problem
DOKUNTAG solution guides
You do not need to know the DOKUNTAG name first. Pick the task you need to finish and get the short answer, steps, free browser tool, and the phone app when it is useful.
How to reduce a photo to a target KB or MB size on iPhone
If the requirement is a file-size limit, set the target in KB or MB instead of guessing a quality percentage. Image Tools DOKUNTAG can prepare a smaller output toward that target on the device, then you review the result before saving it as a new file.
How to resize a photo to exact pixels, mm or cm on iPhone
Use pixels when a website gives a digital dimension such as 600×600 px. Use mm or cm when the requirement is expressed as a physical size. Image Tools DOKUNTAG supports px, %, mm and cm resizing and lets you set the DPI used to translate a physical size into pixels.
How to convert JPG, PNG and WebP on iPhone
Choose the output format based on what the destination accepts, not only on which extension looks familiar. Image Tools DOKUNTAG can convert JPG, PNG and WebP on the device and save the converted result as a new file.
How to remove extra spaces and duplicate lines from text on iPhone
For messy copied text, treat whitespace cleanup and duplicate-line removal as separate operations. Text Tools DOKUNTAG keeps the source and live preview visible, so you can apply a cleanup step, inspect the result, then copy, share, or save a new TXT file without overwriting the source.
Not sure where to start?
Follow the publishing workflow when your task spans several checks or you do not yet know which tool or guide comes first.
Guides and tools support preparation. Always verify current official platform rules before publishing.