6 CSV edge cases that broke my "simple" CSV to JSON converter

GoToolsOnline — Mon, 19 Oct 2026 07:20:49 +0000

I run a small free tools site, and this week I audited its CSV to JSON converter against what its help text promised. The help text said "RFC 4180" and "auto-detects delimiters". The code split the file on newlines and then on commas. Here is what broke, and what the rewrite does instead.

1. Line breaks inside quoted fields

name,note
Asha,"line one
line two"

Splitting on \n first turns this into three broken rows. The fix is a small state machine that walks characters and only ends a row on a newline that is outside quotes.

2. Escaped quotes

In CSV a literal quote inside a quoted field is written twice: "He said ""hi""". A parser that just strips the outer quotes leaves you with He said ""hi"".

3. Spaces inside quotes are data

" Mumbai " should stay " Mumbai ". The old code trimmed every field, which silently changes values. Only trim when the user asks for it, and never inside quotes.

4. Not every "CSV" uses commas

European Excel exports often use semicolons; database dumps use tabs or pipes. Auto-detecting is simple if you count candidate delimiters on the first lines while ignoring characters inside quotes, then let the user override it.

5. Type conversion should be cautious

Converting "42" to 42 is helpful. Converting a PIN code or employee ID like 007 to 7 is data loss, and a 20-digit order ID turned into a JavaScript number loses its last digits (anything above 2^53 is not exact). My rule now: numbers only when they round-trip exactly, true/false/null as literals, everything else stays a string.

6. An unclosed quote should be an error, not a guess

If the file ends while still inside quotes, the old parser happily swallowed the rest of the file into one cell. Now it reports the problem, because a wrong JSON output that looks fine is worse than an error.

The other direction (JSON to CSV)

Two things matter most: nested objects need flattening (user.address.city as a column) and every field containing the delimiter, a quote, a line break or leading/trailing spaces must be quoted. If the CSV is going into Excel, writing a UTF-8 BOM keeps non-English text from turning into mojibake.

Takeaway

CSV looks trivial until real files arrive. If your tool's description promises a standard, write a test file for each edge case above and run it before you ship.

Disclosure: the converters I rewrote are on my site, GoToolsOnline. Both run in the browser, so the data isn't uploaded: https://gotoolsonline.com/tools/csv-to-json

How to convert CGPA to percentage (and why the 9.5 rule isn't universal)

GoToolsOnline — Tue, 13 Oct 2026 07:57:04 +0000

Many students need to convert a CGPA into a percentage for job applications, scholarship forms, or further study. The conversion looks simple, but the right formula depends on which body issued your grade sheet.

The commonly cited formula

For CBSE results, the formula most often quoted is:

percentage = CGPA x 9.5

Worked example: a CGPA of 8.2 gives 8.2 x 9.5 = 77.9%

The 9.5 rule isn't universal

The 9.5 factor is a CBSE convention. Many universities publish their own conversion formula, and the factor can be different. Anna University, VTU (Visvesvaraya Technological University) and Mumbai University each publish their own rules, so a figure calculated with 9.5 may not match what your university expects.

Before you convert anything, check:

The conversion rule on your university's website, result notice, or FAQ.
Whether your university issues a conversion letter or states a percentage on your transcript.
What the receiving organisation asks for. Some forms accept the university's document; others ask you to state the formula you used.

Averaging SGPA into CGPA: weight by credits

If you only have semester SGPA values, your overall CGPA is usually a credit-weighted average, not a simple average:

CGPA = (sum of SGPA x credits) / (sum of credits)

Example: Semester 1 has SGPA 8.0 for 20 credits, and Semester 2 has SGPA 7.5 for 24 credits.

(8.0 x 20 + 7.5 x 24) / (20 + 24) = 340 / 44 = about 7.73

Quick tips

Use the credit totals from your university's scheme, not the number of subjects.
Keep the decimal places your university uses, and round only at the end.
Check whether repeated or cleared subjects count toward the credit total under your rules.
Keep the official document with your calculation when you submit a form.

Disclosure: I run GoToolsOnline, which has a free no-signup calculator for this: https://gotoolsonline.com/tools/cgpa-to-percentage

DEV Community: GoToolsOnline