HelloCSV alternative with spreadsheet editing and formulas
Updog's grid behaves like a spreadsheet. Users paste ranges from Excel, drag a fill handle, write formulas, and fix a whole column, with full undo behind every step.
100% client-sideWhite-label1M+ rows
Updog and HelloCSV at a glance
| Dimension | Updog | HelloCSV |
|---|---|---|
| Data privacy | Files are parsed, validated, and edited in the browser. Row data never reaches Updog's servers, so there is no data processor, DPA, or residency to manage. | An open-source (MIT) importer that runs entirely in the browser; its creators built it specifically as a frontend-only alternative to Flatfile and OneSchema, which send data to remote servers. Nothing is uploaded: parsing, mapping, validation, and fixes all happen client-side, and saved progress is stored in the browser's IndexedDB, so it never leaves the user's browser. As a self-hosted library there is no vendor, so compliance certifications, a DPA, and data residency do not apply. |
| White-label | Full styling through CSS variables and class overrides. No Updog logos or "powered by" on any plan, including the free one. | Theming through color variables for primary, secondary, and tertiary elements plus status colors, a few preset themes, and configurable width and height. As an MIT library it carries no vendor branding. Dark mode and logo customization were not found. |
| Pricing | Free for development, and a 14-day trial with no card when you go live. In production, a flat $19 per domain per month, the same at any volume, and your first paid domain includes a free one for staging. | Free and open-source under the MIT license. No paid tiers or usage fees. |
| Data mapping | Schema in code. Fuzzy column matching with a built-in synonym dictionary you can extend, or connect the AI your organization already approves through a hook, so it runs on infrastructure you control with no new AI vendor to clear. Updog keeps no mapping history. Your app owns that state and can supply saved selections on later imports. Maps incoming values to your options. Auto-detects number and date formats. Combines files by upserting on a key. | You define your columns up front, and a dedicated step maps the file's headers to them, with mapping suggestions you can customize. There is no built-in AI matching. It also handles multiple sheets in one import, including linking one sheet to another and deduplicating shared records across them. |
| Data cleaning | Cells edit inline through a typed editor per column, text, number, date, select, or multi-select, with clipboard, fill handle, and full undo and redo. Values pass a transform on the way in, then validation runs at three levels, built-in rules, your own checks, and asynchronous ones. Sorting, full-text search, filters on the columns you enable, and formulas. Invalid rows can block submit or come through flagged. Any view also exports in any supported format. | A preview step where users review and fix their data before confirming, editing cells inline as needed. Built-in validation covers required, unique, regex, list membership, integer, email, phone number, and postal code, plus your own custom rules. Automatic formatters, such as phone-number formatting, run with a preview so users can see what changed. Progress is saved in the browser, so edits survive a refresh. No find & replace or undo/redo found; it is an import-and-fix flow with an editable preview, not a full spreadsheet editor. |
| Scale & performance | About one million rows at around 20 columns in the browser, with a filter on every column. No fixed row cap, the browser tab's memory is the ceiling, and fewer columns reach further. Filtering and sorting run in a worker, measured at 30 to 250 milliseconds over a million rows. | Client-side and lightweight, with a roughly 99kb footprint. CSV and TSV are handled natively; other formats, including Excel, need a small adapter you write to convert them to CSV first. You can cap the accepted file size, but no maximum row count is documented, so throughput is bound by browser memory. |
| Integration | React component, plus a Web Component for Vue, Angular, Svelte, and vanilla JS. Renders inline in your page's DOM. Imports CSV, TSV, Excel, JSON, and XML, plus any other format through a parser you register yourself. | Ships React, Preact, and vanilla JavaScript builds, plus a CDN option, so it drops into any app regardless of framework, even one that does not use React. When the user finishes, your app receives the cleaned rows, along with import stats and the processed file if you want to send it to your own server. Written in TypeScript. |
| Languages & RTL | English by default, with every interface string overridable, so you can localize into any language. Right-to-left is first-class. It flips layout, text alignment, scrollbars, and column pinning, and carries through to export. | Three built-in interface locales, English, French, and Brazilian Portuguese, and you can supply your own translations. No right-to-left support was found. |
| Accessibility | An ARIA grid with full keyboard navigation and screen-reader support. WCAG 2.2 AA is the level Updog builds to, with automated rule checks over every component and every step of the importer on each test run. Updog holds no independent audit or VPAT. | No accessibility statement found. The preview is a real HTML table with a label on every cell, cells carry button roles rather than grid semantics, and the source has no keyboard handlers. |
HelloCSV is an MIT-licensed, frontend-only CSV importer, first released in March 2025 and positioned as a free Flatfile and OneSchema alternative that keeps data in the browser. Facts checked against HelloCSV's public pages in July 2026.
Which one fits your team
HelloCSV may fit better if
- You want a free, open-source MIT importer that runs entirely in the browser and sends nothing to a server.
- You need to embed an import-and-fix flow in any app, whether React, Preact, or vanilla JavaScript, with a small bundle.
- You are happy defining columns and validation in code and fixing rows in an editable preview rather than a full spreadsheet editor.
- You mainly import CSV or TSV, with Excel handled through a custom file loader, at moderate scale.
Updog may fit better if
- You want an importer and spreadsheet editor embedded in your own app.
- You want to match your app's design exactly, styling the editor with your own CSS through variables and class overrides.
- You want to handle large files in the browser, with nothing stored on a server.
- You want flat, public pricing with no per-import fees.
- You want to use the AI your organization already approves, with no new vendor to clear.
Questions people ask
Is Updog a drop-in replacement for HelloCSV?
Not quite. Both are client-side importers that embed in your app and send nothing to a server, but Updog is also a full spreadsheet editor, not only an import-and-fix flow.
How do the two handle data privacy?
Neither sends row data to a vendor. Both run entirely in the browser, and HelloCSV even keeps saved progress in the browser's IndexedDB.
How does Updog pricing compare?
Updog is a flat $19 per production domain per month, free in development. HelloCSV is free and open-source under the MIT license, with no paid tiers.
Can Updog handle large files like HelloCSV?
Yes, about 1 million rows in the browser, bound by the machine's memory. HelloCSV sets no row limit but publishes no large-file benchmark, so it is likewise bound by browser memory.
Can Updog be used to view or edit existing data, without an import?
Yes. Load existing data straight into Updog's editor to view and edit it, with a read-only mode. HelloCSV's editable preview is part of the import-and-fix flow, not general editing of existing data.
How do the two handle accessibility?
Updog's grid uses ARIA semantics with full keyboard navigation and screen-reader support, and the importer is checked against WCAG 2.2 A and AA rules on each test run. Updog holds no independent audit or VPAT. No accessibility statement was found for HelloCSV: its preview is a real HTML table with a label on every cell, cells carry button roles rather than grid semantics, and the source has no keyboard handlers.
Can the interface be translated, and does right-to-left work?
Updog ships in English with every interface string overridable, so you can localize into any language, and it renders right-to-left layouts natively. HelloCSV has three built-in locales, English, French, and Brazilian Portuguese, accepts your own translations, and no right-to-left support was found.
See how Updog compares to other CSV importers
Try Updog for free
Install the package, add your columns, render the component. Free on localhost and preview domains. Every feature included.