Developer & data
Base64 text codec
Base64 text codec: UTF-8 text ↔ RFC 4648 Base64. Not encryption.
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Developer & data
Choose a tool. The method, example and assumptions are included.
Developer & data
chmod numeric permission calculator
Decode a Unix permission mode into owner, group and other read, write and execute permissions.
Developer & data
CRC-32 text checksum
Calculate the standard reflected CRC-32 checksum of the exact UTF-8 bytes of text you enter.
Developer & data
CSV pivot by group and sum
CSV pivot by group and sum: Group exact cell strings and sum the selected numeric column with decimal arithmetic.
Developer & data
CSV to JSON
CSV to JSON: Parse CSV header row into an array of string-valued objects; reject duplicate or empty headers.
Developer & data
CSV to Markdown table
CSV to Markdown table locally in your browser, with clear input requirements, a worked example and an explanation of the result.
Developer & data
Extract a column from CSV
Extract one CSV column as a JSON array, with an optional spreadsheet-safe one-column CSV download.
Developer & data
Extract email-like addresses and web URLs
Extract email-like addresses and web URLs: Find conservative email-like ASCII tokens or HTTP(S) URL tokens, remove duplicates and return the first occurrence order.
Developer & data
Filter a JSON object array
Filter a JSON object array: Parse the match as a JSON scalar, then keep objects whose own named property is exactly equal in both type and value.
Developer & data
Filter CSV rows by a column
Filter CSV rows by a column: Parse CSV and retain rows whose selected cell equals, contains, or differs from the entered case-sensitive text.
Developer & data
Find and replace within a CSV column
Find and replace within a CSV column: Parse CSV, replace every exact case-sensitive occurrence in the selected column only, and serialize valid CSV.
Developer & data
Find duplicate CSV keys
Find duplicate CSV keys: Build exact composite keys from the selected cells.
Developer & data
Flatten JSON to pointer entries
Flatten JSON to pointer entries locally in your browser, with clear input requirements, a worked example and an explanation of the result.
Developer & data
HTML entity encoding
HTML entity encoding: Encode five HTML-sensitive characters as entities; output remains plain text
Developer & data
Integer base converter
Integer base converter: Parse safe integer in base 2–36 and format in destination base
Developer & data
IPv4 subnet and CIDR calculator
Find an IPv4 network range, subnet mask, broadcast value and conventional usable host range from a CIDR prefix.
Developer & data
Join two CSV tables by a key
Join two CSV tables by a key: Match exact parsed key strings using a map.
Developer & data
JSON minifier
JSON minifier: Parse and serialize JSON without optional whitespace
Developer & data
JSON path and type report
JSON path and type report: Walk the JSON structure, using [] for each array item position, and count observed value types at each structural path.
Developer & data
JSON string escape and unescape
JSON string escape and unescape locally in your browser, with clear input requirements, a worked example and an explanation of the result.
Developer & data
JSON structural diff
Compare JSON values structurally and list added, removed or changed paths without treating key order as a change.
Developer & data
JSON to CSV
JSON to CSV: Serialize an array of flat primitive-valued objects with the same keys as the first row. Prefix spreadsheet formula values with an apostrophe.
Developer & data
JSON validator and formatter
JSON validator and formatter: Parse JSON without executing it, then serialize with two-space indentation
Developer & data
JWT payload decoder
JWT payload decoder: Decode the base64url JSON payload. Does not verify signatures, trust, issuer, audience or expiry.
Developer & data
Merge CSV tables with matching headers
Merge CSV tables with matching headers: Validate that both parsed header rows match exactly, then append all data rows from the second table to the first.
Developer & data
Redact selected JSON fields
Redact selected JSON fields: Parse JSON, validate all pointers against the original document, then replace each selected value with the string [REDACTED].
Developer & data
Remove duplicate CSV rows
Remove duplicate CSV rows locally in your browser, with clear input requirements, a worked example and an explanation of the result.
Developer & data
Select a JSON value with JSON Pointer
Select a JSON value with JSON Pointer: Traverse own properties and array indices using RFC 6901 JSON Pointer.
Developer & data
SHA-256 text hash
SHA-256 text hash: SHA-256 via Web Crypto; UTF-8 input, hexadecimal digest
Developer & data
Sort a JSON object array by a property
Sort a JSON object array by a property: Require the selected property on every object with the chosen type.
Developer & data
Sort CSV rows by column
Sort CSV rows by column: Use a stable sort by the chosen parsed cell.
Developer & data
Sort JSON object keys
Sort JSON object keys locally in your browser, with clear input requirements, a worked example and an explanation of the result.
Developer & data
Split a CSV column by a literal delimiter
Split a CSV column by a literal delimiter: Split the selected parsed cell by a literal delimiter.
Developer & data
Summarize a numeric CSV column
Summarize a numeric CSV column: Parse nonblank selected cells as numbers; calculate count, sum, mean, minimum and maximum using decimal arithmetic.
Developer & data
Transpose CSV rows and columns
Transpose CSV rows and columns: Treat every CSV row as data and swap row/column indices: output[j][i]=input[i][j].
Developer & data
TSV and CSV converter
TSV and CSV converter: Parse the selected source delimiter with quote handling, then serialize with the destination delimiter and spreadsheet formula escaping.
Developer & data
Unpivot wide CSV columns
Unpivot wide CSV columns: Keep the selected identifier; turn every other cell into a separate row with the source column name and cell value.
Developer & data
URL component encoding
URL component encoding: Encode or decode a URL component; not an entire URL
Developer & data
URL query builder and parser
Build, append or inspect a URL query string with browser-standard encoding, duplicate parameter support and no network request.
Developer & data
UTF-8 text and binary converter
Encode text as 8-bit UTF-8 binary bytes or decode binary bytes into validated UTF-8 text.
Developer & data
UTF-8 text and hexadecimal bytes
UTF-8 text and hexadecimal bytes: Encode text with UTF-8 and format each byte as two hexadecimal digits; decode pairs of hex digits using a fatal UTF-8 decoder.
Developer & data
UUID format and version checker
UUID format and version checker locally in your browser, with clear input requirements, a worked example and an explanation of the result.
Developer & data
vCard 3.0 contact file generator
vCard 3.0 contact file generator: Escape text backslashes, commas, semicolons and line breaks; emit a UTF-8 vCard 3.0 with FN, EMAIL, TEL and ORG fields.