Parquet Lens

a fast viewer for parquet, avro, tfrecord, arrow ipc and feather v2 datasets of any size. open a .parquet, .avro, .tfrecord, .arrow, .arrows, .ipc or .feather file and read it as a table. use it as a parquet viewer, or to preview parquet and arrow files before you load them in code. the schema and row count of a parquet file come from its footer, read in 8 ms on a 5,000,000-row, 101 MB file; rows decode as you scroll to them and search streams the whole file. the viewer is free for every format. pro, a subscription, adds whole-file filter queries, export, exact stats and grid themes, and it is on from the first open: each machine gets a 30-day pro trial with no key to enter, and the status bar counts it down from "Pro trial, 30 days left". in Cursor, Windsurf and VSCodium, install it from Open VSX.

Free - the full viewer, for files of any size

• Metadata-first open: a parquet file shows its schema, row count and row groups from the footer before any data decodes, whatever the file size.
• Exact types: a virtualized table with int64 and decimals at full precision, timestamps with their unit and timezone, nested lists, structs and maps as JSON.
• Whole-file search: match navigation, case toggle and matches only, which pages through the hit rows alone.
• Go to row: Ctrl+G, the row, Enter.
• Schema view: logical and physical types, nullability, codecs, encodings, and the footer's per-column null counts and min/max.
• Row detail: pretty-printed values and one-click copy; copy visible rows as CSV.
• Codecs and framing: parquet snappy, gzip, zstd, lz4 and lz4_raw, plus lz4- and zstd-compressed feather batches; Arrow IPC file and stream, including dictionary-encoded columns and legacy v4 framing.
• Avro: object containers, with the row count from the block headers, so the last row of a big file is one jump away; codecs null, deflate, snappy and zstandard; nested records, arrays and maps show as readable cells, and decimals, dates, times, timestamps and uuids decode to their values.
• TFRecord: tf.Example and tf.SequenceExample records, gzip or zlib compressed too; both checksums of every record are verified at open; each feature key becomes a column, a feature with one value shows as a plain cell and longer ones as a list; image bytes show their type and size instead of hex.
• Open With: an Open With editor and the default for these binary formats.
• Private: runs locally. no account, no telemetry. the free viewer makes no network calls; a key makes one activation call when you paste it, a license check about once a week after that, and one release call when you remove it. the trial start is kept in .twilightventures-lens.json in your home folder as well as in VS Code.

for a parquet file the row count and the schema come from the footer before any row decodes, and the grid asks for rows in pages of 200 as you scroll, read from the file by position. a list, struct or map column stays one column under its schema name, with the value rendered as JSON in the cell, clipped at 200 characters there and shown whole in the row detail. a timestamp column reads as a date and time to the microsecond, with UTC after it when the file stores the value as UTC-adjusted, rather than as an integer. the extension runs on VS Code 1.90 or newer. it claims .parquet, .pq, .parq, .avro, .tfrecord, .tfrecords, .tfrec, .tfrecord.gz, .tfrecords.gz, .tfrec.gz, .arrow, .arrows, .ipc, .feather and .ftr, and nothing else: a .csv or .json file is not touched. the status bar item shows only while a Parquet Lens tab is active; the pro dialog appears only when you click a pro item.

Pro, optional subscription

• Filter queries: country == "US" && amount > 100, tested against every row with the column's own type; the grid becomes the matching rows, search runs inside them, and export can take them.
• Export: all rows, filter matches or search matches, to csv or jsonl, with a cancelable progress bar. never over the source file.
• Exact stats: the schema view's full scan computes nulls, min, max, mean and distinct counts from every row instead of the footer statistics.
• Themes: twelve looks for the grid: default, hacker, cyberpunk, goblincore, neon, nosferatu, halloween, blue lagoon, duskhollow, abyss, obsidian and moonlit garden, each tuned for light and dark editors. run Parquet Lens: Pick theme to try one; trying is free for the window, keeping it is pro. the default look never changes.

the trial has four notices, each shown when a Parquet Lens tab is in front. one comes inside the last seven days, with the days left in it rather than seven every time, and another on the final day; those two stay out of a sitting that asks you for a review, and never both show in one session. a third comes once the trial has ended. it reads "Your Lens Pro trial has ended. Get Lens Pro to keep whole-file filters, export, exact stats and themes.", and after it the free viewer stays as it was. the fourth comes first, when the trial starts: "Lens Pro is on for 30 days on this machine: whole-file filters, export, exact stats and themes. No key needed.". a machine sees each of the four once, and a key entered stops all of them. all four carry two buttons, Buy (personal) and Business pricing, which open the two checkouts of the Get Lens Pro pick in the status bar menu. the other three start with what the trial did, as in "This trial: 3 filter queries, 1 export.", and all four end with the price. besides those, the first time a filter query, an export or an exact stats run produces something during the trial, with more than seven days of it left, one plain message names it, as in "That filter query was Pro. Your trial runs 27 more days. Search reads every row for free."; it comes once and has no button. every pro dialog names the feature, "Whole-file filter is a Lens Pro feature." for the filter box, ends with the price and offers three buttons, Buy (personal), Enter license key and Business pricing; an export or a full-scan stats run turned down leaves the same price line in a note on the grid. the command palette has the pair as Parquet Lens: Get Lens Pro and Parquet Lens: Enter license key, and the status bar item opens a menu with both and Write a review.

one Lens Pro key covers Parquet Lens, JSONL Lens and Log Lens for VS Code, but the three do not pass the key between them. paste it into each one you use; the Remove license key command in that extension releases that activation again.

$4.90 a month or $49 a year personal, $9.90 a month or $99 a year business: one key for all three extensions, and Pro stays on in every build while the subscription runs. a personal key activates on up to 3 machines, a business key on 10, all three extensions on each (each extension on each machine is one activation: 9 on the personal key, 30 on the business key); release a machine from the Polar customer portal. when the subscription ends, Polar revokes the key and Pro turns off at the extension's next check, about once a week; the free viewer stays.

buy on polar (personal, business), then run Parquet Lens: Enter license key.

receipts, invoices, your subscription, your key and its activations are in the Polar customer portal at polar.sh/twilight-ventures/portal; cancel there any time. sign in with the purchase email. for a refund, write to support@twilightventures.dev. a refund revokes the key.

the free viewer is the complete viewer, not a demo. everything that was free in 0.1.0 stays free in every later build; pro adds the four items above and nothing is taken away.

Part of the Lens family

• JSONL Lens for VS Code: the same table, search and schema view for JSON Lines files; a jsonl export from here opens straight in it.
• Log Lens for VS Code: the same table and search for log files, with a filter per level.
• On JetBrains IDEs: Parquet Lens, JSONL Lens and Log Lens - one engine, a shared filter grammar, exports that open in each other.

Guides and support

the guides and the family overview are at twilightventures.dev. write to support@twilightventures.dev about anything to do with Parquet Lens or a purchase, suggestions included; for a bug, name the version and the rough size of the file. bugs and requests can also go on the issues page of the Lens repository.

in your language

한국어: Parquet Lens는 크기에 상관없이 Parquet, Avro, TFRecord, Arrow IPC, Feather v2 데이터셋을 VS Code에서 표로 엽니다. Parquet 파일의 스키마와 행 수는 푸터에서 읽고, 행은 스크롤하는 대로 디코딩되며, 검색은 파일 전체를 스트리밍 방식으로 읽습니다. 뷰어는 모든 형식에서 무료입니다. 구독형 Pro는 파일 전체 필터 쿼리, 내보내기, 정확한 통계, 그리드 테마를 추가하며, 처음 열 때부터 켜져 있습니다. 컴퓨터마다 30일 Pro 체험이 라이선스 키 입력 없이 시작됩니다. 확장이나 구매에 관한 문의와 제안은 한국어로 보내 주셔도 됩니다 (support@twilightventures.dev).

**中文：**Parquet Lens 可在 VS Code 中以表格形式打开任意大小的 Parquet、Avro、TFRecord、Arrow IPC 和 Feather v2 数据集。Parquet 文件的 Schema 和行数来自 Footer，各行在滚动到时解码，搜索则流式读取整个文件。查看器对所有格式免费。订阅制的 Pro 版增加全文件过滤查询、导出、精确统计和表格主题，并且从第一次打开起就已启用：每台机器都有 30 天 Pro 试用，无需输入许可证密钥。关于扩展或购买的问题和建议，欢迎用中文发邮件至 support@twilightventures.dev。

**日本語：**Parquet Lens は、サイズを問わず Parquet、Avro、TFRecord、Arrow IPC、Feather v2 のデータセットを VS Code で表として開きます。Parquet ファイルのスキーマと行数はフッターから読み取り、行はスクロールに応じてデコードされ、検索はファイル全体をストリーミングで読みます。ビューアーはどの形式でも無料です。Pro（サブスクリプション）はファイル全体のフィルタークエリ、エクスポート、正確な統計、グリッドテーマを追加し、最初に開いたときから有効です。各マシンで 30 日間の Pro トライアルが、ライセンスキーの入力なしで始まります。拡張機能や購入についてのお問い合わせやご提案は、日本語でも support@twilightventures.dev までお送りいただけます。

Türkçe: Parquet Lens ile Parquet, Avro, TFRecord, Arrow IPC ve Feather v2 veri kümeleri, boyutu ne olursa olsun VS Code'da tablo olarak açılır. Bir Parquet dosyasının şeması ve satır sayısı footer'dan okunur, satırlar kaydırdıkça decode edilir ve arama dosyanın tamamını akış halinde okur. Görüntüleyici her biçim için ücretsiz. Pro, abonelikle satın alınır; tüm dosya üzerinde filtre sorguları, dışa aktarma, kesin istatistikler ve tablo temaları ekler. İlk açılıştan itibaren her makinede 30 günlük Pro denemesi, lisans anahtarı girmeden kendiliğinden başlar. Uzantı veya satın almayla ilgili sorularınızı ve önerilerinizi Türkçe de yazabilirsiniz: support@twilightventures.dev.

Português: O Parquet Lens abre datasets Parquet, Avro, TFRecord, Arrow IPC e Feather v2 de qualquer tamanho como tabela no VS Code. Schema e contagem de linhas de um arquivo Parquet vêm do footer, as linhas são decodificadas conforme você rola, e a busca percorre o arquivo inteiro em fluxo contínuo. Para todos os formatos, o visualizador é gratuito. O Pro é vendido por assinatura e acrescenta consultas de filtro no arquivo inteiro, exportação, estatísticas exatas e temas de grade, e já vem ativo desde o primeiro uso: cada máquina ganha um teste gratuito de 30 dias do Pro sem digitar nenhuma chave de licença. Dúvidas e sugestões sobre a extensão ou uma compra podem vir em português para support@twilightventures.dev.

Deutsch: Parquet Lens öffnet Parquet-, Avro-, TFRecord-, Arrow-IPC- und Feather-v2-Datasets jeder Größe als Tabelle in VS Code. Schema und Zeilenzahl einer Parquet-Datei stammen aus ihrem Footer, Zeilen werden beim Scrollen dekodiert, und die Suche liest die ganze Datei als Stream. Der Viewer ist für jedes Format kostenlos. Pro gibt es im Abonnement; es ergänzt Filterabfragen über die ganze Datei, Export, exakte Statistiken und Tabellendesigns und ist vom ersten Öffnen an aktiv. Jeder Rechner bekommt eine 30-tägige Pro-Testphase, ohne dass ein Lizenzschlüssel eingegeben werden muss. Fragen und Anregungen zur Erweiterung oder zum Kauf gern auf Deutsch an support@twilightventures.dev.