Every row, proven before you cast on.
Paste a knitting pattern. Stitchproof reads it, counts every stitch in every size, and shows you exactly where the numbers don't add up, and how to fix them.
Free, no account. Standard patterns are read entirely in your browser.
Rnd 49
size Adult LThe instructions make 65 stitches; the pattern says 64.
5 later rounds go wrong because of this one.
Suggested fix
Change 8 to 7 in Rnd 49 (size Adult L only).
With this edit, every row in every size adds up.
October 22, 2026
Etsy banned AI-written patterns. Buyers still can't tell which ones they are.
Etsy now prohibits AI-generated knitting, crochet and other craft patterns, after admitting that many buyers “can't tell which items involve AI-generated content.” A knitwear designer told CBC her sales had halved since those patterns appeared.
A rule needs evidence. A pattern whose stitch counts cannot work is evidence anyone can check, and Stitchproof finds it in seconds: which row, which size, by how many stitches. Designers get the same check before they publish.
AI reads the words. Code counts the stitches.
Language models write pattern-shaped text without keeping a running total. That's why AI-generated patterns so often don't work. Stitchproof only trusts AI to translate. Every count is plain arithmetic you can check.
- 1
Read
The offline reader understands standard notation. Only lines it can't read are sent to a small AI model, which rewrites them in strict notation, copying every number, never correcting it. The parser then checks that translation before anything is counted.
- 2
Count
Every stitch is defined by how many stitches it uses and how many it makes: k2tog uses 2 and makes 1, a yarn-over uses none and makes 1. Each row is walked stitch by stitch, for every size, and compared with the count the pattern promises.
- 3
Fix
When a row doesn't add up, Stitchproof tries small edits to that row's numbers, re-counts the whole pattern for each, and suggests the one that makes everything agree, or tells you the printed count is the typo.
We broke correct patterns on purpose.
Every number in six correct patterns (cast-ons, repeat counts, stitch counts and stated totals, in every size) was changed by ±1 and ±2, the typos designers actually make. Then Stitchproof proofed and fixed each broken copy on its own.
- 450
- single-number typos, made in 6 correct patterns
- 100%
- of the 423 typos that change a stitch count were caught
- 100%
- of those were repaired so every row adds up again
- 89.4%
- were restored to the designer's exact original text
The other 27 typos change no stitch count (for example, how many plain rows to knit), so no count-based check can see them. Recomputed on every build by lib/stitch/evaluate.ts; run it yourself with npx tsx scripts/eval-fixer.ts.
Who it's for
- Designers
- Check every size before you publish, and catch the errata your test knitters would have found on row 40. Send them a proof link instead of a spreadsheet.
- Knitters
- Check a pattern before you buy yarn, then knit it one row at a time with the count to expect and each row in plain English.
- Buyers
- Check a pattern before you pay for yarn. If the numbers can’t work, copy a plain-text report with the exact rows and send it to the seller or the marketplace.