137 free tools that run entirely in your browser

Run Python, Go, Rust, Bash, JavaScript, and 15+ more languages side by side — multi-pane, with stdin, in a sandboxed executor. No setup.

Animate with code — a tiny DSL of shapes and moves plays on a canvas. Scrub the timeline and export a video (WebM) or PNG, all in your browser.

Generate production-ready Kubernetes YAML (Deployment, Service, Ingress, ConfigMap, HPA, CronJob) with dry-run lint checks and a live resource visualizer.

Plan Kubernetes capacity: pods-per-node bin-packing, node count, monthly cost, and packing efficiency — plus a CPU/memory unit converter (millicores, Mi, Gi).

Validate Kubernetes manifests in your browser — structure, deprecated APIs, and workload best practices (unpinned images, missing probes, privileged pods).

Generate Kubernetes NetworkPolicy YAML — default-deny, allow from pod/namespace/CIDR, egress with DNS — from a simple form.

Generate a Kyverno ClusterPolicy from common guardrails — disallow :latest, require limits/probes/non-root, restrict registries, require labels.

Generate a KEDA ScaledObject from a form — Prometheus, Kafka lag, CPU/memory, or cron triggers, with min/max replicas and scale-to-zero.

Paste a `docker run …` command and get an equivalent Docker Compose service — ports, volumes, env, network, and restart policy.

Build Prometheus queries visually — metrics, label matchers, rate windows, aggregations, quantiles — with plain-English explanations and ready-made templates.

Lint a Dockerfile against hadolint-style rules with a security grade — unpinned images, missing USER, cache bloat, secrets — plus a multi-stage generator.

Generate systemd .service and .timer unit files from a form — dependencies, restart policy, resource limits, and a schedule — with a ready-to-install command.

Turn key/value inputs into a clean terraform.tfvars file with correct HCL typing (strings, numbers, bools, lists, maps), plus matching variable declarations.

Generate a Kubernetes Ingress from a form — multiple hosts with their own path rules, TLS via cert-manager, and the nginx annotations you actually reach for.

Build an OpenTelemetry Collector config — pick receivers, processors, exporters, and pipelines; memory_limiter first, batch last, ready to deploy.

Convert an availability target (99.9%, 99.99%…) into allowed downtime per day, week, month, and year, then track error-budget burn — the core SRE math.

Turn recovery-time and recovery-point objectives into a backup cadence and DR tier, with a data-loss and downtime risk read-out. ISO 22301 / 27031 style.

Model exponential backoff with full or equal jitter — see per-attempt delays, the jitter range, and cumulative wait. The AWS retry math, visualized.

Paste a set of numbers to get count, mean, median, standard deviation, and p75/p90/p95/p99 — the latency percentiles SRE teams track.

Paste tcpdump output for a traffic summary — top talkers, ports, protocol/flag mix, and heuristics for refused connections, dropped SYNs, and scans.

Look up A, AAAA, MX, TXT, NS, CNAME, and SOA records for any domain over DNS-over-HTTPS — with TTLs and DNSSEC status, straight from your browser.

Find who is behind any IP address — ASN, network owner, hosting or carrier, geolocation, and reverse DNS — the classic "whose IP is this" lookup for triage.

Fetch the live TLS certificate chain from any https URL or host:port — issuer, SAN list, expiry countdown, key type, and chain trust. No openssl needed.

Resolve an IP address back to its PTR / reverse-DNS hostname and forward-confirm the match — the FCrDNS check that mail servers and allowlists rely on.

Check whether a DNS record change has propagated by querying multiple public resolvers around the world and comparing their answers side by side.

Audit a domain's email DNS in one shot — MX, SPF, DKIM, and DMARC records — and flag missing or misconfigured policies that hurt deliverability.

Check whether a single TCP port is reachable on a host — a quick connectivity test for firewalls, security groups, and services during an incident.

Paste an AWS IAM policy to spot wildcard actions, over-broad resources, public principals, and privilege-escalation paths — with a least-privilege grade.

Break any AWS ARN into partition, service, region, account, and resource, with validation notes. Build one from fields too.

Grade HTTP response headers against the OWASP secure-header baseline — HSTS, CSP, cookie flags, MIME-sniffing, clickjacking — with fixes.

Generate the current 2FA code from a base32 TOTP secret (RFC 6238, like Google Authenticator) with a live countdown — computed locally.

Turn a username and password into an HTTP Authorization: Basic header and its base64 token — encoded entirely in your browser.

Decode X.509 PEM certificates in your browser — subject, issuer, SANs, validity, key type, and SHA fingerprints. Nothing leaves your machine.

Decode JSON Web Tokens client-side: header, payload, human-readable timestamps, expiry status, and optional HS256 signature verification.

Mask emails, IPs, tokens, JWTs, cards, and secrets out of pasted logs before sharing them in a ticket or screenshot — in the browser, nothing uploaded.

Hash a password with bcrypt at a chosen cost factor, and verify a plaintext against an existing bcrypt hash — entirely in your browser.

Decode a PKCS#10 Certificate Signing Request — subject (CN, O, OU…), SANs, public key type and size, signature algorithm — and verify its self-signature.

Check whether an SSL certificate, private key, and CSR belong together by comparing their public keys. Your private key never leaves the browser.

Convert certificates between PEM, DER, PKCS#7 (.p7b), and PKCS#12 (.pfx) — bundle a cert and key into a .pfx or extract them back out. All in your browser.

Encrypt and decrypt text with a password using AES-256-GCM and a PBKDF2 key — salt and IV are bundled in the output. Runs entirely in your browser.

Password-encrypt any file with AES-256-GCM and download the result — decrypt it later with the same password. The file never leaves your browser.

Generate an RSA key pair (1024/2048/4096) as PEM, then encrypt with the public key and decrypt with the private key using RSA-OAEP. All local.

Score a password on entropy, character variety, and common patterns — with an estimated crack time and concrete warnings. Or generate a strong one.

Build a Content-Security-Policy directive by directive or from a preset, import an existing policy to edit, and get header, nginx, and meta-tag snippets.

Format, minify, validate, and sort JSON with precise error locations — plus one-click JSON to YAML conversion.

Convert YAML to JSON and back, entirely in the browser. Handles the block-style YAML used by Kubernetes, CI pipelines, and configs.

Encode and decode Base64 (standard and URL-safe) with full UTF-8 support, plus hex output — the way Kubernetes Secrets expect it.

Compare two texts line by line with additions and deletions highlighted — configs, manifests, or anything else.

Convert a JSON array of objects to CSV and back — with quoting, nested-key flattening, and delimiter options — entirely in the browser.

Build Markdown tables in a spreadsheet-style grid, paste CSV/TSV to import, set column alignment, and copy clean GitHub-flavored Markdown.

Query JSON live with JSONPath expressions and see matching values highlighted — for extracting fields from API responses and kubectl -o jsonpath output.

Convert XLSX, XLS, or ODS spreadsheets to CSV — one CSV per sheet — parsed in your browser with SheetJS. No upload.

Turn one or more CSV files into an XLSX workbook — each CSV becomes a sheet. Built in your browser with SheetJS.

Combine multiple spreadsheets into a single workbook (sheets kept separate) or a single stacked CSV — in your browser with SheetJS.

Split a multi-sheet workbook into separate files — one XLSX or CSV per sheet. Runs entirely in your browser.

Convert CSV to delimited plain text — tab, pipe, semicolon, or space separated — with a quote-aware parser. All in your browser.

Convert tab, pipe, semicolon, or space delimited text into properly quoted CSV — in your browser, nothing uploaded.

Split a large CSV into several smaller files by rows-per-file or number of files, repeating the header in each part — in your browser, nothing uploaded.

Turn a JSON sample into TypeScript interfaces or Go structs (with json tags) — nested objects become named types. Great for typing API responses.

Pretty-print SQL — uppercases keywords and breaks SELECT / FROM / WHERE / JOIN clauses onto their own lines, in your browser.

Convert a .env file to JSON or shell export statements and back — auto-detects the input format, quotes values safely. All in your browser.

Encode and decode RFC 4648 Base32 — the alphabet behind TOTP secrets and base32 file encodings. Runs locally, nothing uploaded.

Beautify or minify HTML and run a syntax check — catches unclosed and mismatched tags, stray closers, and duplicate ids. All in your browser.

Parse HTML into a collapsible DOM tree — see every element, its attributes, and a tag-count summary. Uses the browser’s inert parser, so nothing executes.

Beautify or minify CSS and check syntax — flags unbalanced braces, declarations missing a value, unterminated strings/comments, and empty selectors.

Convert Java/Spring .properties files to YAML or JSON and back — dotted keys become nested structures, types are inferred. Auto-detects the input format.

Convert Unix timestamps (seconds/millis auto-detected) to human time in UTC and your zone — and back. Live current-epoch ticker included.

Parse and explain crontab expressions in plain English, preview the next run times, and start from common presets.

Compare a time across cities worldwide and find the best hour to meet — a colour-banded grid shows each city’s working hours, with DST handled automatically.

A Pomodoro focus timer — 25-min focus, 5-min breaks, a long break every 4th round — plus preset countdowns and a chime when time’s up. Runs in your browser.

Generate an Nginx server block — reverse proxy or static/SPA, TLS with HTTP→HTTPS redirect, load balancing, gzip, security headers, and rate limiting.

Generate placeholder text by paragraphs, sentences, or words — with a one-click regenerate for fresh filler.

Paste any git command to see what it does in plain English — with a clear warning before destructive operations like reset --hard, push --force, or clean -fd.

Generate cryptographically random UUID v4s — single or in bulk — straight from your browser’s CSPRNG.

Generate strong passwords, tokens, and API secrets — pick length and character classes, or a memorable passphrase, with an entropy estimate. Browser CSPRNG.

Compute SHA-1, SHA-256, SHA-384, and SHA-512 digests of any text via WebCrypto — hex and Base64 output.

Compute keyed HMAC signatures (SHA-1/256/384/512) for a message and secret via WebCrypto — the way webhooks (Stripe, GitHub) sign and verify payloads.

Build a tailored .gitignore from your stack — languages, frameworks, IDEs, and OS files — using the community gitignore templates, ready to copy.

Generate htpasswd entries for HTTP basic auth (bcrypt, SHA, or APR1-MD5) — the credentials nginx, Apache, and Ingress basic-auth expect.

Convert between HEX, RGB, and HSL, generate a tints-and-shades palette, and check WCAG contrast on white and black. A visual, colorful helper.

Compute the MD5 checksum of any text and verify it against an expected hash. For integrity checks — MD5 is not safe for passwords or security.

Generate a GitHub Actions CI workflow from a form — Node, Python, Go, or Rust with a version matrix, or a multi-arch Docker build-and-push to GHCR/Docker Hub.

Turn any text into a clean URL slug — strips accents and punctuation, with a configurable separator and case.

Spell out text in the NATO phonetic alphabet (Alfa, Bravo, Charlie…) — handy for reading codes, keys, and IDs aloud.

Paste logs to auto-detect the format (JSON lines, logfmt, or plain text), count levels, filter by severity, and read them in a clean table — all client-side.

Encode/decode URL components and dissect full URLs into scheme, host, path, and a query-parameter table.

Expand IPv4 CIDR blocks into network, broadcast, usable range, host counts, and netmask — instantly.

Convert between permission checkboxes, octal (754), and symbolic (rwxr-xr--) notation with a live command preview.

Test JavaScript regular expressions live: matches, capture groups, and highlighted hits as you type.

Build a curl command from a form — method, headers, auth, and body — and get the equivalent fetch() and HTTPie one-liners. Or paste a curl command to decode it.

Split a VPC CIDR into evenly-sized subnets across AZs — network, range, and host counts per subnet, with leftover space shown. Plan before you Terraform.

Convert identifiers between camelCase, snake_case, kebab-case, PascalCase, CONSTANT_CASE, Title Case, and more — for renaming variables, labels, and keys fast.

Escape and unescape strings for JSON, shell single-quotes, regex, HTML, and URL contexts — so a value survives being embedded where you need it.

Build and test Logstash / Grok patterns against sample log lines, watch named captures resolve, and copy the pattern for your ingest pipeline.

Count characters, words, lines, and UTF-8 bytes in any text — with and without spaces — for meta tags, tweets, DB column limits, and commit messages.

Break a User-Agent string into browser, version, OS, device type, and rendering engine — or parse your own browser’s UA in one click.

Parse a shell script for problems — unterminated quotes, unclosed if/for/while/case blocks, and shellcheck-style warnings on shebangs, backticks, and [ ] use.

Check whether a version satisfies a range — caret, tilde, x-ranges, hyphen, AND/OR — and see the resolved comparators. For Helm/npm/image tags.

Searchable reference for every HTTP status code — meaning, when it fires, and how DevOps/SRE teams should treat it. 1xx through 5xx.

Searchable table of well-known TCP/UDP ports and the services behind them — the ports you actually meet in firewalls, security groups, and incident calls.

Combine several PDFs into one file, in any order you choose — reorder before merging. Runs entirely in your browser; your documents are never uploaded.

Extract a page range from a PDF, or split every page into its own file — in the browser, nothing uploaded.

Rotate all pages or specific pages of a PDF by 90, 180, or 270 degrees and download the fixed file — client-side, nothing uploaded.

Turn JPG and PNG images into a single PDF — one image per page, fit-to-image or A4/Letter with margins. Converted in your browser.

Render every page of a PDF to a PNG image at 1×–3× resolution and download them individually or all at once — rendered locally with pdf.js.

Convert PDF pages to JPG images with adjustable quality and resolution, right in your browser — no upload, no watermark.

Stamp a diagonal text watermark on every page of a PDF with adjustable opacity, size, and angle — applied in your browser, nothing uploaded.

Build a clean invoice PDF from a form — parties, line items, tax, and totals — and download it instantly. Generated locally, no sign-up.

Shrink a PDF’s file size with Ghostscript-grade compression at three quality levels — see the before/after size. Processed on the server in memory, not stored.

Add AES-256 password protection to a PDF, remove it when you know the password, or change it — powered by qpdf. Files are processed in memory and not stored.

Remove the password and restrictions from a PDF you can already open — enter the password you have and download an unlocked copy. Not a brute-force cracker.

A drag-and-drop grid of your PDF’s pages — reorder, rotate, duplicate, or delete any page, then save. Rendered and rebuilt entirely in your browser.

Remove specific pages or page ranges from a PDF and download the trimmed file — client-side, nothing uploaded.

Draw your signature and stamp it onto any page of a PDF at the corner and size you choose — applied in your browser, nothing uploaded.

Freeze interactive PDF form fields into fixed page content so entered data can’t be changed — flattened in your browser with pdf-lib.

Permanently black out text or areas in a PDF — draw boxes and the page is flattened to an image, so the underlying text is truly removed, not just hidden.

Convert DOC, DOCX, or ODT documents to PDF with faithful styling using headless LibreOffice. Files are processed on the server in memory and not stored.

Convert XLSX, XLS, ODS, or CSV spreadsheets to PDF with LibreOffice rendering. Processed on the server in memory, not stored.

Convert PPT, PPTX, or ODP presentations to PDF with LibreOffice. Processed on the server in memory, not stored.

Convert a PDF to an editable Word (DOCX) document via LibreOffice. Best on simple, text-based PDFs — complex layouts and scans may not convert cleanly.

Extract a PDF into an editable Excel (XLSX) workbook via LibreOffice. Tabular PDFs convert best; heavily formatted or scanned PDFs may need cleanup.

Extract text from photos, scans, and image-based PDFs using Tesseract OCR in your browser (WebAssembly). Nothing is uploaded — the first run fetches ~11 MB.

Convert images between WebP, JPG, and PNG in your browser with an adjustable quality slider — batch-convert many at once. Nothing is uploaded.

Shrink images by scale or max-width, strip EXIF metadata, and re-encode as WebP/JPG/PNG to cut file size — see the before/after. All in your browser.

Record from your microphone and play it back — with a live input-level meter and a speaker test tone to confirm your mic and speakers work. Nothing uploaded.

Grade your writing — reading level, Flesch ease, and Gunning Fog — with inline highlights for hard sentences, adverbs, passive voice, and complex words.

Turn any text into a word cloud sized by frequency, with stop-words removed and a downloadable PNG. Rendered on a canvas in your browser.

Dictate text using your browser’s speech recognition in 10 languages, with live transcription you can edit, copy, or download. Nothing is stored or uploaded.

Play continuous white, pink, or brown noise to focus or relax — generated live with the Web Audio API, no files, works offline. Adjustable volume.

Validate an IBAN with the ISO 7064 mod-97 checksum and break out the country code, check digits, and BBAN.

Estimate net take-home pay from gross salary in the US, UK, India, Canada, Australia, Ireland, Singapore, Germany, and UAE, with an effective-rate breakdown.

Calculate the tip and split a bill between any number of people, with quick tip presets and a per-person total. Runs in your browser.

Convert integers (1–3999) to Roman numerals and back, with validation that rejects malformed numerals.

Convert between Celsius, Fahrenheit, Kelvin, and Rankine — see all four scales at once from one value.

Convert between binary, octal, decimal, and hexadecimal — plus byte-size (KiB/MiB vs KB/MB) conversions engineers reach for daily.

Evaluate expressions with parentheses, powers, constants (pi, e), and trig/log/sqrt functions — safely parsed, no eval(). Radians or degrees. In your browser.

Convert between units of length, mass, volume, area, speed, and data size (1000- and 1024-based) with an instant, swappable result. Runs in your browser.