complete working app for stemlm.

Lint, format and rewrite SQL online across PostgreSQL, MySQL, Snowflake and BigQuery with risky-query warnings and safe rewrites.

Render LaTeX math to SVG, PNG, PDF and accessible MathML in the browser using KaTeX or MathJax with font, theme and accessibility controls.

Query and patch YAML, JSON, TOML and XML configs in your browser with jq, JSONPath, JMESPath and JSON Patch - comments, anchors, and key order preserved.

Compare DOCX versions online, accept or reject tracked changes, extract comments and convert Word to clean HTML or Markdown.

Compare two OpenAPI or JSON Schema specs online and find breaking changes per operation with migration patches and SDK impact preview.

Generate Open Graph social cards and syntax- highlighted code screenshots online - themes, fonts, line highlights and brand templates.

Sanitise, optimise, rasterise and diff SVGs online - strip XSS, resolve fonts, build sprites, render to PNG, WebP and AVIF at exact DPI.

Extract audio, run EBU R128 loudness normalisation, generate waveform peaks and Chromaprint fingerprints online for podcast and video.

Run DuckDB SQL on CSV, JSON, JSONL, Parquet and SQLite files in the browser - joins, EXPLAIN plans and bounded result downloads.

Stream-process CSV, TSV, NDJSON and JSONL in your browser with Miller-style verb chains, joins, pivots and dialect sniffing.

Trim, concat, remux video and generate thumbnails, contact sheets, sprite sheets and shot boundaries online with FFmpeg.

Parse PDFs into RAG-ready Markdown and JSONL chunks online with reading order, headings, tables, code blocks, captions and OCR.

Write, test and benchmark grok and Logstash patterns online with field inference, ReDoS warnings and exports for Vector and Fluent Bit.

Remove EXIF, GPS, XMP, IPTC and MakerNotes metadata from JPEG, PNG, HEIC, PDF, MP3 and MP4 - privacy presets and prove-clean reports.

Subset, convert and QA TTF, OTF, WOFF and WOFF2 fonts online - glyph coverage, variable-font instancing and WOFF2 output in the browser.

Compare PDFs visually and structurally online - per-page masks, text and object diffs, signature checks and human-readable summaries.

Generate styled Excel XLSX from declarative JSON online with charts, formulas, conditional formatting, merged cells, tables and images.

Check DNS, RDAP, TLS, certificate chain, ASN and socket banners online - with DNSSEC validation, CT logs and expiry alerts.

Diff two GraphQL schemas online and find breaking and dangerous changes - operation coverage and federation composition checks.

Convert Markdown, DOCX, HTML, LaTeX, EPUB and PDF online via Pandoc with templates, citations, filters and math support.

Compile Typst documents to PDF, SVG, PNG and HTML online with pinned versions, package universe, fonts and a live editor playground.

Compare Excel XLSX workbooks online at cell, formula, style, chart, named-range and sheet-structure level with tolerance settings.

Render PowerPoint PPTX slides to PNG, JPEG, SVG and PDF online, extract speaker notes, embedded media and fonts, and swap assets.

Detect file types from magic bytes online - MIME mismatch, ambiguity, container sniffing and risk flags for Office macros and polyglots.

Convert, normalise, mux and burn SRT, VTT, ASS and TTML subtitles online into MP4, MKV and WebM with timing and encoding fixes.

A free, fast directory of browser-based developer tools - SQL on CSV, PDF utilities, OpenAPI diffs, log analysis and more. No installs, no accounts. Built with Next.js, deployed on Vercel.

Fill, flatten and validate PDF AcroForms online from JSON, FDF or XFDF with appearance regeneration and field inspection.

Online HTML extractor and CSS selector tester — query, scrape, and parse HTML with CSS selectors, extract attributes, text content, pretty-print output, strip elements. Runs in browser, no install.…