Subnet & CIDR Calculator
Turn an IPv4 address and CIDR prefix into network address, broadcast, usable host range, host count and wildcard mask.
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37 tools
IP Address Format Converter
Convert an IPv4 dotted-quad address between binary, hexadecimal, octal and 32-bit integer representations instantly.
Open calculatorPort Number Lookup
Identify which well-known service listens on a TCP/UDP port number, drawn from a static table of common assignments.
Open calculatorMIME Type Lookup
Look up the Content-Type MIME type for a file extension, with an honest fallback for extensions without a standard mapping.
Open calculatorChmod Calculator
Convert Unix file permissions between symbolic (rw-r--r--) and octal (644) notation with a per-class numeric breakdown.
Open calculatorDownload Time Calculator
Estimate how long a file transfer takes at a given connection speed, with bits versus bytes handled correctly.
Open calculatorAPI Pagination Calculator
Compute page count, offset and item placement for paginated APIs; including honest handling of pages beyond the range.
Open calculatorStorage Growth Calculator
Project data volume after months of compound growth, with added-capacity figures and optional monthly cost impact.
Open calculatorUptime SLA Calculator
Translate an availability percentage into the exact downtime budget per day, 30-day month and year, humanized as clock time.
Open calculatorError Budget Calculator
Track how much of your SLO-derived error budget remains after recorded downtime, with a healthy-or-breached status.
Open calculatorSRE Burn Rate Calculator
Compute how fast you are consuming error budget relative to plan, benchmarked against Google SRE fast-burn conventions.
Open calculatorAWS EC2 Cost Calculator
Estimate hourly, monthly and yearly EC2 on-demand cost for common us-east-1 instance types from a static snapshot price table.
Open calculatorAWS S3 Cost Calculator
Estimate monthly S3 spend from storage volume, PUT/GET request counts and internet egress using snapshot tier pricing.
Open calculatorLLM Token Counter
Estimate how many tokens a piece of text consumes using character-based and word-based heuristics, plus an optional cost line.
Open calculatorLLM API Cost Calculator
Project monthly LLM API spend from per-call token usage, input/output pricing and call volume across your traffic mix.
Open calculatorContext Window Calculator
Check whether your system prompt, conversation history and reserved response fit inside a model’s context window.
Open calculatorRAG Chunking Calculator
Work out how many chunks an overlapping-window chunking strategy produces, plus stored-token overhead and embedding cost.
Open calculatorEmbedding Storage Calculator
Size the memory footprint of a vector collection from count, dimensions and precision, including index overhead and RAM guidance.
Open calculatorGPU Memory Calculator
Estimate GPU memory for running a model from parameter count, precision, batch size and KV cache allowance, with fit checks.
Open calculatorModel Size Calculator
Compute on-disk model weight size in decimal GB and binary GiB, plus download time over a 100 Mbps link.
Open calculatorConcurrency & Throughput Calculator
Apply Little's law to solve the missing variable among arrival rate, latency and concurrent requests, with capacity guidance.
Open calculatorRate Limit Planner
Convert an API quota into a safe sustained requests-per-second budget with pacing intervals and burst headroom.
Open calculatorJSON Formatter & Validator
Validate JSON and reformat it with pretty indentation or minify it to a single compact line, with precise parse-error positions.
Open calculatorBase64 Encoder & Decoder
Convert text to Base64 and back with full UTF-8 support; multilingual characters and emoji survive every round trip.
Open calculatorURL Encoder & Decoder
Percent-encode query-string components or whole URLs, and decode escaped strings back; malformed escapes are caught cleanly.
Open calculatorHTML Entity Escaper & Unescaper
Escape the five HTML-critical characters (& < > " ') or unescape named, decimal and hexadecimal entities back to plain text.
Open calculatorJWT Decoder
Decode JWT header and payload claims with base64url-safe parsing, plus live expiry analysis against the current clock.
Open calculatorUUID v4 Generator
Generate one to fifty random UUID version-4 identifiers using crypto.randomUUID with a documented RFC 4122 fallback.
Open calculatorULID Generator
Generate lexicographically sortable ULIDs; Crockford base32 timestamps plus 80 bits of monotonic randomness per the spec.
Open calculatorSecure Password Generator
Build random passwords from selectable character classes with guaranteed coverage, ambiguity filtering and entropy estimates.
Open calculatorPassword Strength Calculator
Estimate password entropy from detected character classes and translate it into average offline crack time at your attack-speed assumption.
Open calculatorSHA Hash Generator
Compute SHA-1, SHA-256, SHA-384 and SHA-512 digests of any text at once using the browser’s native WebCrypto engine.
Open calculatorHMAC Generator
Compute keyed HMAC-SHA-256/384/512 signatures for API requests and webhook verification using native WebCrypto.
Open calculatorUnix Timestamp Converter
Convert Unix seconds, milliseconds or ISO 8601 strings into every other format automatically, with relative-time context included.
Open calculatorCron Expression Parser
Translate five-field cron expressions into plain English, validate every field range and list the next scheduled run times.
Open calculatorRegex Tester
Test regular expressions against sample text with live match counts, highlighted matches and capture-group breakdowns.
Open calculatorCase Converter
Convert any text into camelCase, snake_case, kebab-case, PascalCase, CONSTANT_CASE and four more conventions simultaneously.
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