Free tools
Small tools that answer one question each. They compute in your browser, so nothing you paste is uploaded, and none of them ask you to create an account.
On this site
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Chinese text analyzer
Paste Chinese text for its character count, the HSK level it sits at, and the characters above that level.
Characters · HSK 1-6 coverage · reading time
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Flashcard workload calculator
See where a spaced repetition habit plateaus in reviews per day, and what it costs in minutes, before committing to a new-card rate.
Steady-state reviews · ramp-up · minutes per day
From the products
These live on the product sites they belong to. Same rule: they run in the browser and need no account.
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QR code generator
Turn any link into a QR code and download it as PNG or SVG.
ShortLink
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UTM builder
Build campaign URLs whose parameters attribute correctly in analytics.
ShortLink
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Best time to post
Get a simple posting window for each day of the week, per platform.
SchedulePost
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Caption character checker
Compare a caption against the character limit of each platform before you post it.
SchedulePost
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Video aspect ratio checker
Check a video's dimensions against what each platform accepts before you upload.
SchedulePost
Why these exist
Every tool here started as a question that came up while building the four products, and that was faster to answer with a page than with a paragraph. Each one states the method it uses and the source of any data it depends on, so the output can be checked rather than taken on trust.
If a tool gives you a result that looks wrong, the input that produced it is worth sending to hello@fulinlabs.com.