FileNestCalm file work
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Free forever · Files stay local

Online Batch File Renamer

Drop in a folder's worth of files, combine prefix, suffix, text replacement and numbering rules, then review every old-to-new name before download.

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File contents stay local Review first, then run
DATA HANDLING BEFORE YOU STARTCore processing stays in this browser; signed-in features store service metadata such as account, quota and jobs, not copies of your work files.
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STEP 01Add files

Choose files from your device; their contents are not uploaded.

STEP 02Choose settings

Combine rules and adjust file order at any time.

STEP 03Review & download

Review every name, resolve conflicts and package the copies.

FREE + PROCore batch renaming stays free; Pro adds advanced naming workflows.Core renaming does not consume conversion credits. Pro adds regex, CSV filename mapping, saved templates and task history.
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DATA HANDLING DETAILSOpen the full data boundary when you want the implementation details.
Full data handling matrix
Processed in this browserCore file processing runs on this device; the work files do not need to be uploaded to FileNest first.
File contents are not uploadedWork files stay on this device for this tool; outputs are generated or downloaded within the browser workflow.
Service metadata ≠ file copiesSigned-in features may store account, quota, job, download or saved-rule records; those records do not contain copies of your work files.
Practical use cases

Less mechanical sorting, more focus

Client delivery

Standardize attachments with project names, versions and delivery order.

Event photos

Keep extensions while adding a date, prefix and zero-padded sequence.

File archives

Replace an old project name across a batch without touching file contents.

FAQ

Questions before you begin

Will this overwrite my original files?

No. FileNest downloads renamed copies inside a ZIP. Your originals remain unchanged.

Are files uploaded to a server?

No. Name previews and ZIP packaging happen inside your current browser.

Will file extensions be lost?

Extensions stay on by default, and the preview shows the exact final result before download.

Related tools

Keep the next batch organized

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01, 02, 03 — sorted in one passRename Files in Sequential OrderYour order — not the computer'sCustom Order File RenamerCount backward from the last itemReverse Number File Renamer
COMMON TASKS

Batch edit filenames with prefixes, replacement and numbering

When many filenames need the same cleanup, add the files first and build the rule while watching the before-and-after preview. Combine prefixes, suffixes, text replacement and numbering, resolve conflicts, then download renamed copies instead of changing the originals in place.

Batch edit file names

Add a shared prefix or suffix, replace repeated text and keep the original extensions without editing filenames one by one.

Sequential numbering and zero padding

Number the current order with a chosen start, increment and padding so names such as 001, 002 and 003 sort predictably.

Preview first, then download copies

Rename preview and ZIP packaging run in the current browser, and FileNest does not overwrite originals. Use Pro regex, CSV mapping or saved templates when structured naming becomes recurring work.

Invoice filename mapping: approve each target first

For one common prefix, use the free basic rule. If each invoice needs a different approved customer ID, review original,new pairs before considering Pro CSV mapping. Check missing rows, duplicate targets and extensions before download; FileNest does not verify customer identity.

Batch rename diagram: preview report.pdf and notes.txt renamed to client_001.pdf and client_002.txt before downloading ZIP copies; originals stay unchanged.
Example names only. Check every new name, extension and conflict before downloading; this is not a live tool screenshot.
Practical guide

Understand the workflow before processing the file

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Directly related to this toolHow to batch rename files without uploading themDirectly related to this toolShould batch renaming use regex, a CSV map or basic rules?
Tests & product evidence

What evidence supports this workflow?

Only evidence directly relevant to this tool is listed below, with its testing or disclosure boundaries.

Preview-First Batch Safety Evidence

Review production behavior for preflight previews, collision and unsafe-name blocking, original-file protection and image-batch de-duplication.

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File Processing Privacy Matrix

Check whether current working-file contents stay browser-local or use an explicitly disclosed transient-cloud path.

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