Developer Utilities
Small developer utilities that save a trip to a random website. Encode and decode Base64, explain a regex, build UTM links, generate QR codes and vCards, and more — the everyday helpers. Free in your browser, and available by API when you need them in a script.
Developer Utilities
MAC address type analyzer
unicast, multicast, universal or local
POST /dev/mac-type$0.002Developer Utilities
Merge Sort Comparisons Calculator
Worst and Average Cases
POST /dev/merge-sort-comparisons$0.002Developer Utilities
TCP window size for throughput
BDP calculator for LFN
POST /dev/tcp-window-for-throughput$0.002Developer Utilities
WiFi channel frequency calculator for 2.4 GHz and 5 GHz
POST /dev/wifi-channel-freq$0.002Developer Utilities
Amdahl's Law Speedup Calculator
Find Parallel Scaling Limits
POST /dev/amdahl$0.002Developer Utilities
Hash bits for collision resistance
birthday bound bit length
POST /dev/hash-bits-for-collision$0.002Developer Utilities
Hash table load factor calculator
check resize threshold
POST /dev/hash-load-factor$0.002Developer Utilities
Binary Heap Children Index Calculator
POST /dev/heap-children-index$0.002Developer Utilities
Huffman code length calculator
optimal lengths and total bits
POST /dev/huffman-code-length$0.002Developer Utilities
Recursion tree node count calculator
levels and work distribution
POST /dev/recursion-tree-nodes$0.002Developer Utilities
Required operations per second calculator
meet a deadline
POST /dev/required-ops-per-second$0.002Developer Utilities
Row-major array index calculator
offset and byte address
POST /dev/array-rowmajor-index$0.002Developer Utilities
Balanced brackets validator
check bracket nesting and mismatches
POST /dev/balanced-brackets$0.002Developer Utilities
Binary tree max nodes calculator
nodes and leaves by height
POST /dev/binary-tree-max-nodes$0.002Developer Utilities
Code comment line counter
measure documentation density
POST /dev/count-comments$0.002Developer Utilities
Edge list to adjacency matrix converter
POST /dev/edges-to-adjacency-matrix$0.002Developer Utilities
Graph vertex degree calculator
in-degree, out-degree & handshake lemma
POST /dev/graph-degree$0.002Developer Utilities
English word pluralizer
regular and irregular noun plurals
POST /dev/pluralize-word$0.002Developer Utilities
Struct field offset calculator
C offsetof, size, and padding
POST /dev/struct-field-offset$0.002Developer Utilities
Tabs to spaces converter
expand tab indentation to spaces, free
POST /dev/tabs-to-spaces$0.002Developer Utilities
Sørensen–Dice string similarity calculator
bigram coefficient free online
POST /dev/dice-coefficient$0.002Developer Utilities
Levenshtein Edit Distance Calculator for Two Strings
POST /dev/levenshtein$0.002Developer Utilities
Longest common subsequence calculator
LCS length and one instance
POST /dev/longest-common-subsequence$0.002Developer Utilities
Requests per second to daily converter for traffic planning
POST /dev/qps-to-daily$0.002Developer Utilities
Repeated substring pattern detector
smallest unit and count
POST /dev/repeated-substring$0.002Developer Utilities
Servers needed for load calculator
capacity with safety headroom
POST /dev/servers-needed$0.002Developer Utilities
Batch throughput calculator
batch size, interval and target rate
POST /dev/batch-throughput$0.002Developer Utilities
RAID capacity calculator
usable space, FT & overhead
POST /dev/raid-capacity$0.002Developer Utilities
SemVer range satisfies checker
test package versions
POST /dev/semver-satisfies$0.002Developer Utilities
Token bucket rate limit calculator
burst allow/deny, refill & wait time
POST /dev/token-bucket$0.002Developer Utilities
ANSI truecolor generator
convert HEX or RGB to 24-bit terminal color
POST /dev/ansi-truecolor$0.002Developer Utilities
MIME Type to File Extension Lookup
POST /dev/extension-from-mime$0.002Developer Utilities
Glob pattern to regex converter
shell wildcards to regular expression
POST /dev/glob-to-regex$0.002Developer Utilities
Key Length to Keyspace Calculator
Compare 56, 128, and 256 Bits
POST /dev/key-space-bits$0.002Developer Utilities
Query String to JSON Converter
Decode URL Parameters
POST /dev/query-string-to-json$0.002Developer Utilities
Rendezvous hashing node selector
highest-random-weight pick for a key
POST /dev/rendezvous-hash$0.002Developer Utilities
Screen resolution pixel calculator
megapixels & framebuffer memory
POST /dev/screen-pixels$0.002Developer Utilities
SI vs IEC byte converter
manufacturer GB vs OS GiB
POST /dev/si-vs-iec-bytes$0.002Developer Utilities
Umask calculator
default file and directory permissions from umask
POST /dev/umask-calculator$0.002Developer Utilities
UUID format validator
check version, variant and canonical form
POST /dev/uuid-validate$0.002Developer Utilities
Acronym Generator for Projects, Variables, and Constants
POST /dev/acronym-generate$0.002Developer Utilities
Hamming ECC parity bits calculator
how many r for m data bits
POST /dev/ecc-parity-bits$0.002Developer Utilities
Fenwick tree index calculator
parent & next via LSB
POST /dev/fenwick-index$0.002Developer Utilities
HTTP Range header calculator
parse and build byte ranges
POST /dev/http-range-header$0.002Developer Utilities
IPv6 to binary converter
expand an address to 128 bits
POST /dev/ipv6-to-binary$0.002Developer Utilities
Quarterly Compound Interest Calculator
Future Value
POST /finance/compound-interest-quarterly$0.002Developer Utilities
Effective Annual Rate Calculator
Convert Nominal Rate to EAR
POST /finance/effective-annual-rate$0.002Developer Utilities
Rule of 72 required rate
annual return to double in N years, free
POST /finance/rule-of-72-rate$0.002Developer Utilities
Annuity payment from future value calculator
POST /finance/annuity-payment-from-fv$0.002Developer Utilities
Effective rate including fees calculator
all-in annual rate
POST /finance/effective-rate-with-fees$0.002Developer Utilities
Future Value of Ordinary Annuity Calculator
POST /finance/future-value-annuity-ordinary$0.002Developer Utilities
Implied interest rate calculator
rate from PV, FV and periods
POST /finance/interest-rate-from-pv-fv$0.002Developer Utilities
Loan refinance savings calculator
compare payments and interest
POST /finance/loan-refinance-savings$0.002Developer Utilities
Loan total interest calculator
fixed-rate amortizing loan cost
POST /finance/loan-total-interest$0.002Developer Utilities
Negative Amortization Balance Calculator
POST /finance/negative-amortization-balance$0.002Developer Utilities
Perpetuity Present Value Calculator
POST /finance/perpetuity-present-value$0.002Developer Utilities
Student Loan Payment Calculator
Monthly Payment and Total Repayment
POST /finance/student-loan-payment$0.002Developer Utilities
Loan APR from fees calculator
true APR with financed fees
POST /finance/loan-apr-from-fees$0.002Developer Utilities
15 vs 30 year mortgage calculator
compare payment and interest
POST /finance/mortgage-15-vs-30$0.002Developer Utilities
Home affordability calculator
estimate your maximum home price
POST /finance/mortgage-affordability$0.002