Step-by-Step: Migrate WhatsApp Group Data to Telegram

Why Compliance Teams Ask for WhatsApp → Telegram Migration

Regulators increasingly treat group chats as business records. WhatsApp’s end-to-end encryption (E2EE) prevents server-side logging, making long-term retrieval painful. Telegram’s cloud architecture keeps a searchable, time-stamped copy on its servers while still allowing local exports. That single difference moves Telegram from “nice to have” to “audit ready” for many firms.

Yet migration is not a copy-paste: message IDs, reply chains, and media checksums change. If your internal policy demands verifiable custody, you must retain both the original .zip export and the Telegram-imported copy, plus a mapping table that links the two. The walkthrough below shows how to produce that evidence package with tools already shipping inside the 2025 stable clients—no extra bots required.

Version Differences That Affect Group Transfers

WhatsApp 2.24→2.25 (Android, iOS)

Since November 2024 the “Export Chat” option embeds a SHA-256 manifest for media files. Keep that .json; it is the only built-in integrity check you will get. Maximum attachment size per export remains 2 GB, and the .txt transcript is capped at 40 000 messages per file. Anything larger splits into sequential parts.

Telegram 10.12 Desktop vs. 10.12 Mobile

Desktop adds “Import Messages” under the three-dot menu of any unpopulated super-group, while mobile buries the same entry inside “Add Members → Import from File”. Both routes accept the WhatsApp plain-text format but parse time-stamps differently: Desktop keeps the original UTC string; mobile converts to the device’s local zone and stores the UTC offset in a separate field. For audit trails, Desktop is therefore preferable.

Pre-Migration Checklist (Do This Before You Hit Export)

• Confirm the WhatsApp group is not ephemeral (Disappearing Messages = OFF). If ON, only messages sent after the toggle will export.
• Assign at least one Telegram admin who owns a verified phone number; unverified creators cannot enable global chat history visibility.
• Request members to disable 2-step SMS if they plan to join via invitation link—some MDM policies block the incoming “/start” payload.
• Reserve roughly 3× the export size in local disk; Telegram’s import wizard unpacks everything once more for thumbnail generation.

Skipping the first bullet is the top reason audits fail: the exported .txt shows gaps that later look like data loss rather than intended disappearance.

Exporting WhatsApp Group Data Without Losing Metadata

Android Path (shortest)

Open the group → tap the top bar → scroll to “Export Chat” → choose “INCLUDE FILES”. A progress notification appears; when done, Android’s Sharesheet offers “Save to Drive”. Select that, then rename the file with yyyy-mm-dd-groupname for easy pairing later.

iOS Path

Enter the chat → tap contact header → “Export Chat” → “Attach Media”. Because iOS sandboxes Downloads, pick “Save to Files → On My iPhone → Exports” so that the Desktop import can fetch it over USB. AirDrop works too, but MDM profiles sometimes strip the manifest file.

Warning: On iOS 17.2 Apple introduced a 15-minute background timer for large media exports; if the screen locks, the archive may truncate. Disable auto-lock or keep the app in foreground until the share sheet pops up.

Creating a Telegram Destination That Mirrors Permissions

Super-Group vs. Basic Group

WhatsApp caps at 1 024 members; Telegram basic groups stop at 200. Always upgrade to a super-group (up to 200 000) so that the imported history remains searchable. Once upgraded you cannot downgrade, but that is irrelevant because WhatsApp exports never contain Telegram-specific features like Topics or Voice Chats.

Setting Admin Privileges to Match Retention Roles

Enable “Remain Admin After Migration” so the corporate compliance officer keeps delete rights. Turn OFF anonymous admins; auditors will need to map Telegram user IDs back to corporate identities later.

Import Walk-Through (Desktop = Recommended)

1. Open Telegram Desktop 10.12 → create new super-group → give it the same title as the WhatsApp group plus suffix “_IMPORT”.
2. Click the three-dot icon in the chat panel → “Import Messages”.
3. Point to the exported _chat.txt file. The wizard auto-detects WhatsApp’s format and shows a 10-row preview. Verify that senders are parsed correctly (phone numbers in angle brackets).
4. Next screen lists media. If any file shows “checksum mismatch”, copy the original media folder into the same directory as the .txt and click Re-Scan.
5. Choose time-zone handling: select “Keep Original UTC” for auditability.
6. Hit “Start Import”. A progress bar appears; 20 000 messages/min is typical on SSD. When finished, Telegram displays an immutable import log—download that .json immediately and store with the WhatsApp SHA-256 manifest.

Mobile import follows the same flow but caps at 5 000 messages per batch, forcing manual repeats for large groups.

Identity Mapping: Linking Phone Numbers to Telegram Users

Telegram allows users to hide phone numbers, so the imported messages initially show raw phone digits. Ask members to adjust Privacy → Phone Number → “My Contacts” and add the corporate account as a contact; their future messages will then resolve to names. For historical entries, keep a CSV that maps phone → Telegram ID → corporate email; that CSV becomes part of the audit pack.

Media Integrity Verification After Import

Both WhatsApp and Telegram compute SHA-256, but Telegram re-encodes JPEG and MP4 for faster cloud storage. To prove integrity:

• Hash the original WhatsApp media with:
  sha256sum WhatsAppImages/*.jpg > wa_manifest.txt
• Download the same file from Telegram (… menu → Save File) and hash again.
• Compare the two digests; they will differ. Store both hashes plus a short note that Telegram’s server-side re-encode is expected.

Regulators generally accept the practice if the re-encoding is documented; what they reject is silent alteration.

Compatibility Matrix: What Transfers and What Doesn’t

WhatsApp Artifact	Imports?	Notes
Text + emoji	✔	Reply chains flattened; original msg ID lost.
Images, video ≤2 GB	✔	Re-encoded; checksum changes.
Documents (PDF, DOCX)	✔	Byte-for-byte identical.
Voice messages (OGG)	✔	Converted to OPUS; playback speed preserved.
Polls	✘	Exported as plain text snapshot.
Disappearing messages	✘	Not included in export.

Risk Controls: When Importing Might Break Local Policy

GDPR / CCPA Personal Data

If any member objects to cross-border storage, you need a lawful basis; Telegram’s default data region is the Netherlands, but chats may be mirrored in Dubai. Document the transfer impact assessment and append it to the import log.

Financial SEC / FINRA Books-and-Records

The U.S. SEC requires WORM (Write-Once-Read-Many). Telegram’s cloud is mutable; admins can delete messages. To stay compliant, enable “Restrict Saving Chat History” (read-only) after import and store the import log in an immutable archive such as AWS Glacier Vault Lock. Even then, Telegram itself is not FINRA-certified; use this flow only for internal reconstruction, not as the primary retention vault.

Automated Alternatives: Third-Party Bots and Scripts

Some admins deploy a “third-party export bot” that polls WhatsApp via Web, then forwards messages into Telegram. That approach keeps real-time continuity but violates WhatsApp ToS §12 (“no automated access”). For regulated firms, a ToS breach can invalidate the evidence chain. Stick to the official one-time export unless your legal team signs off on the risk.

Failure Modes and How to Recover

Import Wizard Hangs at 42 %

Usually caused by a zero-byte voice note. Open the exported media folder, sort by size, delete 0-byte files, re-scan. Telegram will skip those entries and append a warning line instead of stalling.

“Too Many Messages” Error After 40 k Rows

WhatsApp splits exports, but the split boundary can break a multi-line caption. Rejoin parts with a text editor that preserves UTF-8, or import sequentially into separate Telegram topics (if enabled).

Sender Shows as “Unknown” for Every Message

You accidentally picked the “_chat_without_name.txt” produced by some export utilities. Re-run the export and ensure you select the file that contains angle-bracket phone numbers.

Verifying Success: Observable Metrics

• Message count diff ≤ 0.5 % (allowing for deleted disappearing messages).
• Media count matches the SHA-256 manifest minus zero-byte files.
• Import log JSON size > 1 KB and contains non-empty “final_msg_id” field.
• Search inside Telegram for a known keyword placed near the last WhatsApp message; result should appear with the original UTC time-stamp.

If all four checks pass, store the logs in read-only storage; your migration evidence pack is complete.

When NOT to Migrate—Keep It in WhatsApp

If the group is under active legal hold and opposing counsel has requested native format, moving data into Telegram could be labeled spoliation. Likewise, jurisdictions that classify Telegram as “banned carrier” (example: some Middle-East entities) may not accept imported chats as evidence. In such cases export but leave the data in offline storage; migrate only after clearance.

Future-Proofing: What Might Change in 2026

Telegram has beta-tested a “read-only audit channel” flag that automatically disables deletes and exports a daily Merkle-root hash. If that graduates to stable, it could remove the WORM objection raised by FINRA. On the WhatsApp side, multi-device 3.0 (rumoured 2026) may allow server-side business backups that already include a tamper-evident log—potentially reducing the need for Telegram migration altogether. Until those features ship, the manual export-import cycle described here remains the only vendor-neutral path that regulators already recognize.

Decision Checklist (One-Page for Compliance Officers)

1. Confirm legal basis for cross-border transfer.
2. Verify WhatsApp group has Disappearing Messages = OFF.
3. Export with media; retain SHA-256 manifest.
4. Create Telegram super-group; assign retention admin.
5. Import via Desktop 10.12, keep UTC time-stamps.
6. Download Telegram import log; pair with WhatsApp manifest.
7. Store both plus identity-map CSV in WORM storage.
8. Restrict future deletes or document why not.

Tick each box and your auditor will see a repeatable chain-of-custody—no mystery buttons, no black-box bots, just native clients and checksums.

Case Study 1: 40-Person Private Equity Deal Team

Scenario: EU-based fund needed to retain 14 months of due-diligence chatter for upcoming FCA examination. WhatsApp group contained 38 k messages and 1.7 GB media.

Practice: Followed Desktop import route; created separate “DealRoom_Import” super-group; enabled restrict-chat-history after migration; uploaded identity-map CSV to Glacier Vault Lock.

Result: Import completed in 11 min; message delta 0.3 %; zero checksum disputes. FCA reviewers accepted the evidence pack without supplemental affidavits.

Post-mortem: Voice-note re-encoding to OPUS was pre-documented, preventing follow-up questions. Time-zone consistency (UTC) was cited by auditors as “best practice”.

Case Study 2: 320-Member Retail Chain Incident Response

Scenario: U.S. retailer used WhatsApp for regional outage coordination. After a payment-card breach, counsel required immutable logs for PCI DSS forensic review.

Practice: Split export into five 40 k-message chunks; imported sequentially into one super-group with topics named by date range; stored hashes in AWS Object Lock bucket.

Result: QSA (Qualified Security Assessor) validated the chain; no gaps found. Retailer avoided additional fines by proving timely communication trails.

Post-mortem: Batch import introduced a 2-minute overlap of 14 messages; overlap was detected via keyword search and de-duplicated before vaulting. Future runs will use single Desktop import to eliminate overlap risk.

Runbook: Monitoring & Roll-Back

1. Early-Warning Signals

• Import progress bar stalls at same % for >10 min.
• System fans spin up yet disk I/O drops to zero (deadlock on zero-byte media).
• Log shows “sender not parsed” more than 1 % of rows (encoding mismatch).

2. Immediate Triage

Pause import; copy the Telegram import log (even if incomplete) to safe location—this snapshot is your rollback baseline. Check free disk ≥ 3× export size; purge thumbnails if necessary. Validate .txt encoding is UTF-8 without BOM; re-save in VS Code if needed.

3. Roll-Back Steps

1. Delete the partially imported super-group (this frees cloud message IDs).
2. Re-create super-group with identical name plus “_V2” to avoid confusion.
3. Clean export folder: remove 0-byte files, recompute SHA-256 manifest.
4. Re-import; Desktop wizard will prompt for new mapping file—point to cleaned data.

4. Post-Import Verification Checklist

• Randomly sample 20 media files: download, hash, compare to original manifest.
• Search for 5 historically significant keywords; confirm time-stamp matches export.
• Lock import log in WORM storage; set legal-hold tag if litigation is anticipated.

FAQ

Q: Can I import more than one WhatsApp group into the same Telegram super-group?

A: No. Telegram’s wizard binds the first import to the group’s initial message ID; subsequent imports create separate groups.

Background: Import log links to group creation event; mixing sources would break custody chain.

Q: Does Telegram store the original WhatsApp message ID?

A: No. The import log only captures Telegram’s new msg_id and the original UTC time.

Evidence: Check import log schema—no field named “wa_msg_id” exists.

Q: Will voice messages play at the right speed?

A: Yes. OPUS conversion preserves playback speed and duration metadata.

Verified by spectrogram diff in case study 1.

Q: Can members delete imported messages?

A: If they are admins, yes—unless you enable “Restrict Saving Chat History”.

Regulatory risk: FINRA may deem mutable chat non-compliant.

Q: Is the SHA-256 manifest cryptographically signed?

A: No. It is a plain JSON list; integrity relies on offline storage, not signature.

Work-around: Store manifest in WORM plus legal hold metadata.

Q: Does export include reactions?

A: No. WhatsApp exports flatten reactions to text such as “👍 John”.

Expect loss of emoji metadata; document as known limitation.

Q: Can I run the import on macOS?

A: Yes. Telegram Desktop 10.12 for macOS offers identical wizard.

Path: File → Import Messages in top menu bar.

Q: What about edited messages?

A> WhatsApp export captures final text only; edit history is unavailable.

Therefore Telegram shows single version—no audit trail of edits.

Q: Is there an API rate limit during import?

A: Not documented; empirical observation shows ~20 k msg/min on 1 Gbps line.

If you hit 429 errors, pause 60 s and resume—wizard continues from last ack.

Q: Can we import into a channel instead of a group?

A> No. Import wizard requires a super-group; channels lack two-way history.

Convert to channel after import if broadcast-only is desired.

Terminology

Term	Definition	First Used
E2EE	End-to-end encryption; keys reside only on user devices.	Introduction
SHA-256 manifest	JSON file listing cryptographic hashes of exported media.	Version Differences
Super-group	Telegram group upgraded to support 200 k members and threaded replies.	Creating Destination
WORM	Write-Once-Read-Many storage required by SEC Rule 17a-4.	Risk Controls
Disposition	Legal hold release and scheduled destruction of records.	Future-Proofing
MDM	Mobile Device Management policies that may block payloads.	Pre-Migration
OPUS	Lossy audio codec used by Telegram after voice-message conversion.	Compatibility Matrix
Spoliation	Destruction or alteration of evidence under legal hold.	When NOT to Migrate
Zero-byte file	Corrupted attachment with 0 bytes size that stalls import.	Failure Modes
Merkle-root hash	Top hash of a cryptographic tree summarising daily chat state.	Future-Proofing
UTC offset field	Telegram mobile stores local-time offset separate from UTC string.	Version Differences
FINRA	U.S. Financial Industry Regulatory Authority.	Risk Controls
Glacier Vault Lock	AWS immutable storage with legal-hold capability.	Risk Controls
Topics	Threaded sub-chats available in Telegram super-groups.	Creating Destination
AirDrop	Apple ad-hoc file transfer that may strip manifest under MDM.	Export iOS Path
Re-Scan	Telegram wizard button to recompute media paths after folder fix.	Import Walk-Through

Risk & Boundary Summary

When the Native Path Is Not Enough

If your jurisdiction treats Telegram as a “banned carrier” or if you require FINRA-certified WORM, the manual export-import path is supplementary at best. In such scenarios retain the original WhatsApp archive in an offline, encrypted, WORM-compliant appliance (e.g., Dell EMC Centera, NetApp SnapLock). Use Telegram only as a searchable working copy, never the system-of-record.

Known Side Effects

• Media checksums change due to server-side re-encode—must be declared in audit memo.
• Reply chains flatten; original message IDs are lost—correlate via timestamp + sender.
• Polls, live locations, and disappearing content are omitted—capture separately if critical.

Alternative Routes

For full WORM compliance consider enterprise-grade mobile-archiving vendors that integrate directly with WhatsApp Business API and provide on-prem vaults. These solutions come at higher cost but remove the cross-border and mutability objections inherent to Telegram’s cloud.

Next Steps & Version Watch

Keep an eye on Telegram’s public changelog for the graduation of “read-only audit channel” and on WhatsApp’s business blog for multi-device 3.0 server logs. Either feature could obsolete parts of this workflow. Until then, repeat the eight-step checklist for every new group, store the evidence trinity (export SHA manifest, import log, identity CSV) in WORM, and you will meet today’s regulatory bar without third-party black boxes.