FileGizmo — Text tools

Compare two texts

Compare two blocks of text line by line and identify additions and removals locally.

Never uploadedYour file stays on this device

Simple by design

Text diff in three steps

Compare an original and revised block of text without uploading drafts, configuration, code, or private notes. FileGizmo performs an ordered line comparison and produces a familiar plain-text result: unchanged lines begin with spaces, added lines with +, and removed lines with -.

The comparison uses a longest-common-subsequence strategy, so matching lines remain aligned even when content is inserted or deleted between them. The summary reports additions and removals separately. A one-million line-pair safety limit prevents accidental browser memory exhaustion; split exceptionally large documents into sections for more focused results.

Everything runs in the current browser page, with no account, stored history, or server transfer. The two source editors remain visible while you review the read-only result. Copy the marked diff into an issue or message, or download it as UTF-8 text. The responsive two-column layout becomes a comfortable vertical comparison on smaller screens.

  1. 1

    Paste the original and changed text

  2. 2

    Compare the documents line by line

  3. 3

    Review copy or download the marked result

Good to know

Frequently asked questions

How are changes displayed?

Unchanged lines begin with spaces, additions with plus, and removals with minus.

Is comparison private?

Yes. Both texts remain in the browser and are never uploaded.

Is line order considered?

Yes. A longest-common-subsequence comparison preserves ordered matching lines.

Are very large comparisons limited?

A one-million line-pair safety limit prevents browser memory exhaustion.